Number of 5-cycles in the n X n rook graph.

Terms

a(0) =0a(1) =0a(2) =36a(3) =288a(4) =1320a(5) =4464a(6) =12348a(7) =29568a(8) =63504a(9) =125280a(10) =230868a(11) =402336a(12) =669240a(13) =1070160a(14) =1654380a(15) =2483712a(16) =3634464a(17) =5199552a(18) =7290756a(19) =10041120a(20) =13607496a(21) =18173232a(22) =23951004a(23) =31185792a(24) =40158000a(25) =51186720a(26) =64633140a(27) =80904096a(28) =100455768a(29) =123797520