This is a "secret" announcement. You are welcome, if you want, to share with friends; we're not announcing it generally for a week or so.
We have a new feature on Brilliant.org called discussion groups. The group I am starting will be dedicated to solving open problems (aka open math problems where nobody knows the answer).
The open problems I'm choosing (and fairly soon after launch, the members of the group will be choosing) don't necssarily require higher mathematics and will be friendly to approach at a lower level.
The idea is that many small ideas from many contributors, put together, might be able to tackle an open problem.
Below is a known solved problem, but it's fairly close in format to the first unsolved one we will do. Feel free to discuss the answer, and ask any other questions you might have in this thread.
Place 8 white knights and 8 black knights on a chessboard (of any size) such that:
Each white knight is attacking 2 other white knights and 2 black knights.
Each black knight is attacking 2 other black knights and 2 white knights.
What's the smallest board needed to do this?
Note: A chess knight moves in an "L" shape either 1 square vertically and 2 squares horizontally or 2 squares vertically and 1 square horizontally, as indicated by the stars above.