A129894 Number of ways of placing non-attacking knights on an n X n chessboard symmetric under horizontal reflection.

1, 2, 4, 26, 35, 821, 1462, 148176, 221880, 96574099, 126381799, 196582061878, 269726664738, 1805524692669120, 2273457768078921, 66873306557904082902, 76981272132177635155, 9380430300181898788236006

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Crossrefs

Sequence in context: A128774 A218258 A186431 * A028386 A362001 A259374

Adjacent sequences: A129891 A129892 A129893 * A129895 A129896 A129897

Keyword

nonn

Author

R. H. Hardin, Aug 25 2008

Status

approved