Number of ways to place 5 nonattacking bishops on an n X n toroidal board.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =120a(5) =6912a(6) =52920a(7) =466944a(8) =1905120a(9) =8647680a(10) =25613280a(11) =81838080a(12) =198764280a(13) =510478080a(14) =1082161080a(15) =2393997312a(16) =4594961280a(17) =9120190464a(18) =16225246080a(19) =29656350720a(20) =49689816120a(21) =85128088320a(22) =135870624120