Number of lines through exactly 4 points of an n X n grid of points.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =10a(5) =4a(6) =4a(7) =20a(8) =44a(9) =36a(10) =64a(11) =124a(12) =200a(13) =236a(14) =272a(15) =308a(16) =548a(17) =692a(18) =852a(19) =1108a(20) =1396a(21) =1452a(22) =1768a(23) =2116a(24) =2496a(25) =2908a(26) =3568a(27) =4292a(28) =5428a(29) =5956