A178352 Number of collinear point triples in a 6 X 6 X 6 X ... n-dimensional cubic grid

0, 20, 372, 5696, 85584, 1324160, 21306432, 354876416, 6065958144, 105562511360

Offset

0,2

Links

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

Formula

Conjecture: a(n) = 2*8^n-9*6^n/2+12^n+18^n/2+10^n. a(n) = +54*a(n-1) -1124*a(n-2) +11304*a(n-3) -55008*a(n-4) +103680*a(n-5). G.f.: 4*x*(-5+177*x-2022*x^2+7488*x^3) / ( (12*x-1)*(6*x-1)*(8*x-1)*(18*x-1)*(10*x-1) ). [R. J. Mathar May 25 2010]

Crossrefs

Sequence in context: A290581 A000564 A365415 * A266736 A019580 A177109

Adjacent sequences: A178349 A178350 A178351 * A178353 A178354 A178355

Keyword

nonn

Author

R. H. Hardin, suggested by R. J. Mathar in the Sequence Fans Mailing List, May 25 2010

Status

approved