Number of ways to place 4 nonattacking grasshoppers on a toroidal chessboard of size n x n.

A190399

Number of ways to place 4 nonattacking grasshoppers on a toroidal chessboard of size n x n.

Terms

    a(0) =0a(1) =1a(2) =54a(3) =1068a(4) =8550a(5) =45873a(6) =177968a(7) =562032a(8) =1519560a(9) =3662625a(10) =8057390a(11) =16477020a(12) =31712850a(13) =58018793a(14) =101639700a(15) =171525568a(16) =280160068a(17) =444636297a(18) =687881890a(19) =1040201500a(20) =1541008350a(21) =2240952065a(22) =3204279960a(23) =4511682288

External references