A153967 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 4 X 4 X 4 subtriangle.

1, 2, 2, 4, 7, 15, 30, 103, 229, 913, 3237, 14316, 56401, 399787, 1756484, 13874163, 97904334, 862620519, 6788122417, 96037644217, 842802659086, 13301955362056, 187438690067450, 3299373199801311, 51852238684408496, 1465485312975753622

Offset

0,2

Links

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

Crossrefs

Sequence in context: A049904 A049906 A014265 * A052949 A014266 A032441

Adjacent sequences: A153964 A153965 A153966 * A153968 A153969 A153970

Keyword

nonn

Author

R. H. Hardin Jan 03 2009

Status

approved