A178299 Number of collinear point 4-tuples in a 6 X 6 X 6 X... n-dimensional cubic grid.

0, 15, 234, 2820, 31176, 333840, 3546144, 37807680, 406924416, 4432154880

Offset

0,2

Links

Table of n, a(n) for n=0..9.

Formula

Conjectures from R. J. Mathar, May 24 2010: (Start)

a(n) = 3*8^n+3*10^n/2-5*6^n+12^n/2.

a(n) = 36*a(n-1) - 476*a(n-2) + 2736*a(n-3) - 5760*a(n-4).

G.f.: 3*x*(5-102*x+512*x^2)/((12*x-1)*(6*x-1)*(8*x-1)*(10*x-1)). (End)

Crossrefs

Sequence in context: A231411 A097185 A372195 * A097582 A351527 A057007

Adjacent sequences: A178296 A178297 A178298 * A178300 A178301 A178302

Keyword

nonn,more

Author

R. H. Hardin, suggested by R. J. Mathar in the Sequence Fans Mailing List, May 24 2010

Status

approved