Number of collinear point 4-tuples in an n X n X n cubical grid.

Terms

a(0) =0a(1) =0a(2) =0a(3) =76a(4) =629a(5) =2820a(6) =9767a(7) =26272a(8) =63162a(9) =135504a(10) =269334a(11) =489204a(12) =870943a(13) =1447460a(14) =2319069a(15) =3613088a(16) =5496580a(17) =8046288a(18) =11646108a(19) =16349868a(20) =22751289a(21) =31151020a(22) =41928083a(23) =55298280a(24) =72845822a(25) =94565584a(26) =121269906a(27) =154010268a(28) =194468499