TITLE: How to place k bishops on an nxn chessboard
QUESTION [14 upvotes]: In how many different ways can k bishops be placed on an nxn chessboard such that no two bishops attack each other? Please try to respond with a formula and explanation.

REPLY [9 votes]: See my book
http://problem64.beda.cz/silo/kotesovec_non_attacking_chess_pieces_2013_6ed.pdf
, page 234-236. Number of ways to place k non-attacking bishops on an n x n board, (n>1)