Pentominous

We found a site with this kind of puzzle
https://www.gmpuzzles.com/blog/pentominous-rules-info/

The pentominoes and the letters

Divide the grid into pentominoes so that no two pentominoes of the same shape (including rotations/reflections) share an edge. A cell with a letter in it must be part of the pentomino shape normally associated with that letter.

Correct solutions earn eternal fame.

You can also see the solution on  https://youtu.be/AKBAJevy0gg

Some borders between pentominoes are already drawn.
 Pentominou 1 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA Nico Looije - The Netherlands Matthijs Coster - The Netherlands Ilse De Boeck - Belgium Pentominou 2 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA
 Pentominou 3 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA Pentominou 4 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA
 Pentominou 5 Elke pentomino moet voorkomen. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands INFINITY Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA

Eight pluses and one min

If you want a tip, put the the mouse on the puzzle.
Solvers:
Aad van de Wetering - The Netherlands
Odette De Meulemeester - Belgium
Nico Looije - The Netherlands
George Sicherman - USA "Surprising!"

 Is an imperfect “o” but you can't want everything ;-)  Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Bert Seghers and  Elke Debrie - Belgie - Proud lion parents of Leo Nico Looije - The Netherlands Marleen Dhondt - Belgium - Mutti of Leo George Sicherman - USA I see the letters C-U-B!

A few more names
 ELS Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Els Coussement - Belgium ILSE Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Ilse De Boeck - Belgium Nico Looije - The Netherlands LUC Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands FILIP (1) Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA FILIP (2) Additional conditions: The same pentominoes may not touch each other diagonally. Every pentomino must be used. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands CHRIS The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands
 EDO Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Edo Timmermans - The Netherlands BERT Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands JANA Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands
 THIJS on the MAT Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Matthijs Coster - The Netherlands Nico Looije - The Netherlands For Matthijs Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands OMER Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Voor Rudy Penne Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Hint? Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Voor Paul Levrie Hint? Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes.

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Aad Thoen - The Netherlands Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Aad Thoen - The Netherlands Nico Looije - The Netherlands

Especially for Leo's Mutti
In the first, Aad put "no dot on the i".
The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes.

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium  I found this very difficult. Started with all possibilities of "S" Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

Aad made a Dutch (same in German!) and an English pentominou especially for "Helmut"
 Helm en ut Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA Helmut Postl - Austria Helmet en e=u Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Helmut Postl - Austria

And some great mathematicians
The mathematicians are especially fond of the X Y and PI!
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

Aad put me in the spotlight. Thanks!
Not easy, an O and a D. But pi is in it!
Nico: "These were quite difficult for the program"
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA I was slow like an ox! Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands
 For the grandchild of George Sicherman. NOLAN Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA Nico Looije - The Netherlands The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

"ku=koe" Dutch for cow.
The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes.

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands George Sicherman - USA

For the weekend we got nice beers.
"Pint" is Dutch for "beer"

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

The same pentominoes may not touch each other diagonally.
Every pentomino must be used.

Solvers:
Aad van de Wetering - The Netherlands
Odette De Meulemeester - Belgium
Nico Looije - The Netherlands

 Not a soft boiled egg ;-) Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Additional conditions: The same pentominoes may not touch each other diagonally. Every pentomino must be used. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

Who wants to make an omelet must first break eggs.
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Additional conditions: The same pentominoes may not touch each other diagonally. Every pentomino must be used. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

We vroegen Aad om er twee te maken voor Bernard (Weet je zijn familienaam?)

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Ilse De Boeck - Belgium Matthijs Coster - The Netherlands Aad Thoen - The Netherlands Els Coussement - Belgium

Solvers:
Aad van de Wetering - The Netherlands
Odette De Meulemeester - Belgium

Nico Looije - The Netherlands

 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA Nico Looije - The Netherlands Aad Thoen - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Aad Thoen - The Netherlands In this exercise, a pentomino may only be used once. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Aad Thoen - The Netherlands

A cat is in Dutch: 'Kat'
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - - USA  Aad Thoen - The Netherlands Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA "It was nice of Aad to put all 12 pentominoes in this one." Aad Thoen - The Netherlands Nico Looije - The Netherlands

Solvers:
Aad van de Wetering - The Netherlands
Odette De Meulemeester - Belgium
Nico Looije - The Netherlands
Els Coussement - Belgium
George Sicherman - USA "2021 is much easier than 2020."

In the first, Aad placed "no dot" for multiplication.
The dot means an intersection of two roads, so the four squares belong to four not the same pentominoes.
The special thing about 2021 is that it is formed by two following integers. It becomes even more amazing when you consider that 2021 is the product of two following primes.
2021 = 2000 + 21 = 40.50 + 3.7 = (45 - 5)(45 + 5) + (5 - 2)(5 + 2) = 45² - 2² = (45 - 2)(42 + 2) = 43.47
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Aad Thoen - The Netherlands Nico Looije - The Netherlands

The year of the ox begins on February 21, 2021
.
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Aad Thoen - The Netherlands George Sicherman - USA "The best Ox is LinOX!" Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium George Sicherman - USA Aad Thoen - The Netherlands
 Vereniging Nederlandse Verkeersvliegers Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Matthijs Coster - The Netherlands Aad Thoen - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Matthijs Coster - The Netherlands Aad Thoen - The Netherlands Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Aad Thoen - The Netherlands

We received a nice puzzle from George:

 Why does an American choose a beer of the Netherlands? Solvers: George Sicherman - USA Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands here is a Belgian version!

In the following puzzles there will be an option: number of different neighboring squares.
A neighbor is both orthogonal and diagonal. Maximum 8, minimum 1.
 I thought the minimum was 2, but Aad refuted this with the following example Aad sent a nice example of a counting box This is an 11x11 with a central counting box with a value of 8, using two sets of pentominoes.

 Neighbors 1 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Matthijs Coster - The Netherlands Neighbors 2 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Neighbors 3  Do you want some hints? Move the mouse pointer over the problem. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands 88731 (it is a prime number) Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Aad Thoen - The Netherlands Nico Looije - The Netherlands Neighbors 5 .Fill the grid with just one pentomino set Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium ( Thanks to FlatPoly) Nico Looije - The Netherlands 88321 (it is a prime number) Each pentomino is used at most twice. Solvers: Aad van de Wetering - The Netherlands Nico Looije - The Netherlands

Brenda

Solvers:
Aad van de Wetering - The Netherlands
Odette De Meulemeester - Belgium

All solvers deserve a flower.
"Tulips from Amsterdam"
TULP = Dutch for TULIP
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Additional conditions: The same pentominoes may not touch each other diagonally. Every pentomino must be used. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Matthijs Coster - The Netherlands Nico Looije - The Netherlands

Our English-speaking participants will also receive a flower.
 Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands Tulip with additional conditions: The same pentominoes may not touch each other diagonally. Every pentomino must be used. Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

It is always party time with these puzzles.

 With 2 onions = UI in Dutch (joke) Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands To finish ( a Dutch puzzle to celebrate Pi Day oog = eye => EPILOOG) Solvers: Aad van de Wetering - The Netherlands Odette De Meulemeester - Belgium Nico Looije - The Netherlands

Can't figure it out and would you like a solution? Send an email.