A153970 Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 9 ones in any 5 X 5 X 5 subtriangle.

1, 2, 2, 4, 7, 12, 22, 77, 142, 532, 1881, 6680, 23965, 163600, 576849, 3866824, 26635009, 176366633, 1204710337, 15393505413, 104674234457, 1334666498849, 17456897665295, 221752333314343, 2885843552520634, 70795502834846238

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Crossrefs

Sequence in context: A325786 A244457 A325908 * A067953 A109070 A169973

Adjacent sequences: A153967 A153968 A153969 * A153971 A153972 A153973

Keyword

nonn

Author

R. H. Hardin Jan 03 2009

Status

approved