OFFSET
0,2
COMMENTS
White pawns attack diagonally up and black pawns attack diagonally down.
En passant capturing is not possible.
LINKS
Code Golf Stack Exchange user feersum, Too many pawns on a chess board.
EXAMPLE
For n = 1 the a(1) = 3 boards are as follows:
+---+---+ +---+---+ +---+---+
| W | W | | B | W | | W | B |
+---+---+ +---+---+ +---+---+
| B | B | | W | B | | B | W |
+---+---+ +---+---+ +---+---+
.
An example of one of the a(2) = 30 boards is:
+---+---+---+---+
| W | W | W | W |
+---+---+---+---+
| B | W | W | W |
+---+---+---+---+
| B | B | W | B |
+---+---+---+---+
| B | B | B | B |
+---+---+---+---+
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Kagey, Oct 25 2017
STATUS
approved