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

Terms

a(0) =0a(1) =0a(2) =126a(3) =2032a(4) =20502a(5) =160696a(6) =929880a(7) =4117520a(8) =15037036a(9) =47368960a(10) =132577826a(11) =336828368a(12) =789558314a(13) =1729320120a(14) =3574328936a(15) =7027309888a(16) =13226773092a(17) =23959787480a(18) =41954706558a(19) =71276149776a(20) =117848892710a(21) =190142197976