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