A129898 Number of ways of placing non-attacking knights on an n X n chessboard symmetric under horizontal and vertical reflection.

1, 2, 2, 10, 7, 63, 38, 1252, 456, 42951, 11051, 2411116, 461788, 300699154, 38535499, 76231743090, 6586274655, 36545866507976, 2160036716063, 34857588279065543, 1397443585027894, 67527452467684091249

Offset

0,2

Links

Table of n, a(n) for n=0..21.

Crossrefs

Sequence in context: A094359 A293060 A293061 * A135996 A141610 A019241

Adjacent sequences: A129895 A129896 A129897 * A129899 A129900 A129901

Keyword

nonn

Author

R. H. Hardin, Aug 25 2008

Status

approved