OFFSET
1,3
COMMENTS
The triangle is irregularly shaped: 1 <= k <= A030978(n). A030978(n) is the maximal number of knights that can be placed on an n X n board.
First row corresponds to n = 1.
Counting "inequivalent ways" means: Rotations or reflections of a placement of knights on the board are considered to be the same placement.
LINKS
Heinrich Ludwig, Table of n, a(n) for n = 1..116
EXAMPLE
The triangle begins:
1;
1, 2, 1, 1;
3, 7, 9, 6, 2;
3, 18, 40, 66, 49, 30, 8, 3;
6, 43, 195, 609, 1244, 1767, 1710, 1148, 510, 154, 31, 6, 1;
...
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Heinrich Ludwig, Jun 10 2014
STATUS
approved