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

A190396

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

Terms

    a(0) =0a(1) =1a(2) =78a(3) =1278a(4) =10002a(5) =50191a(6) =189208a(7) =584958a(8) =1563488a(9) =3737987a(10) =8181786a(11) =16669638a(12) =32003238a(13) =58438623a(14) =102234772a(15) =172344406a(16) =281269668a(17) =446107043a(18) =689807558a(19) =1042679982a(20) =1544166426a(21) =2244921423a(22) =3209227248a(23) =4517779918

External references