A243720 Number of inequivalent (mod D_8) ways to place 5 nonattacking knights on an n X n board.

2, 49, 1244, 12329, 81900, 398907, 1562362, 5153001, 14907120, 38753358, 92417760, 204977323, 427812496, 847346181, 1604300270

Offset: 3

Author

Heinrich Ludwig, Jun 19 2014

Keywords

• nonn
• more

Crossrefs

Cf. A243716, A172136, A243717, A243718, A243719.

Formula

a(n) = (n^10 - 90*n^8 + 240*n^7 + 3235*n^6)/960 + O(n^5) for n >= 8.