Number of collinear point 8-tuples in an n X n cubical grid.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =18a(8) =184a(9) =1030a(10) =4180a(11) =13750a(12) =38896a(13) =98098a(14) =225972a(15) =483412a(16) =972772a(17) =1858020a(18) =3395076a(19) =5966700a(20) =10139220a(21) =16715912a(22) =26838572a(23) =42058890a(24) =64517116a(25) =97018822a(26) =143341936a(27) =208297894