A166214 Number of 6 X 6 X 6 triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= n.

1, 6, 26, 89, 249, 604, 1340, 2718, 5166, 9309, 16010, 26443, 42285, 65576, 99088, 146337, 211677, 300467, 419570, 576863, 782184, 1047233, 1385738, 1813757, 2350697, 3018141, 3841784, 4851076, 6079477, 7564937, 9351702, 11488015

Offset

0,2

Links

R. H. Hardin, Table of n, a(n) for n=0..63

Formula

Empirical g.f.: (1 + 6*x + 22*x^2 + 61*x^3 + 127*x^4 + 196*x^5 + 242*x^6 + 244*x^7 + 193*x^8 + 113*x^9 + 50*x^10 + 16*x^11 + 3*x^12) / ((1 - x)^8*(1 + x)^4*(1 + x + x^2)^4). - Colin Barker, Feb 27 2018

Crossrefs

Sequence in context: A172207 A060101 A036422 * A032169 A032196 A011780

Adjacent sequences: A166211 A166212 A166213 * A166215 A166216 A166217

Keyword

nonn

Author

R. H. Hardin, Oct 09 2009

Status

approved