Number of collinear point 5-tuples in an n X n cubical grid.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =12a(5) =88a(6) =364a(7) =1120a(8) =2876a(9) =6432a(10) =13116a(11) =24640a(12) =43800a(13) =73656a(14) =119160a(15) =185616a(16) =281064a(17) =413008a(18) =594888a(19) =836784a(20) =1157812a(21) =1573912a(22) =2109844a(23) =2784608a(24) =3638980a(25) =4693888a(26) =5996612a(27) =7583488a(28) =9514336a(29) =11822904