A153969 Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 9 ones in any 5 X 5 X 5 subtriangle.

1, 2, 4, 16, 63, 396, 2827, 37617, 513564, 13162553, 341036622, 16622509689, 823228295943, 76578732281797, 7241902334442198, 1280682968270209748

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Crossrefs

Sequence in context: A153960 A339648 A005027 * A153966 A138867 A138868

Adjacent sequences: A153966 A153967 A153968 * A153970 A153971 A153972

Keyword

nonn

Author

R. H. Hardin, Jan 03 2009

Status

approved