A178294 Number of collinear point triples in a 4 X 4 X 4 X... n-dimensional cubic grid.

0, 4, 44, 376, 2960, 22624, 171584, 1303936, 9969920, 76793344

Offset

0,2

Links

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

R. J. Mathar, Points on a line in the finite d-dimensional simple cubic lattice

Formula

Conjecture: a(n) = 8^n/2-3*4^n/2+6^n. a(n) = +18*a(n-1) -104*a(n-2) +192*a(n-3). G.f.: 4*x*(-1+7*x)/((6*x-1)*(8*x-1)*(4*x-1)). - R. J. Mathar, May 24 2010

Crossrefs

Cf. A005059.

Sequence in context: A030987 A341590 A297384 * A043039 A198962 A002754

Adjacent sequences: A178291 A178292 A178293 * A178295 A178296 A178297

Keyword

nonn

Author

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

Status

approved