A153902 Number of planar n X n X n binary triangular grids symmetric under 120-degree rotation with no more than 1 one in any 4 X 4 X 4 subtriangle.

1, 2, 1, 1, 2, 2, 4, 8, 9, 13, 28, 40, 68, 188, 247, 498, 1534, 2240, 5457, 19030, 34984, 92787, 351730, 736460, 2179274, 9660082, 22277066, 75466794, 381461162, 984019235, 3823360536

Offset

0,2

Links

Table of n, a(n) for n=0..30.

Crossrefs

Sequence in context: A083698 A128976 A199627 * A318205 A046772 A348291

Adjacent sequences: A153899 A153900 A153901 * A153903 A153904 A153905

Keyword

nonn

Author

R. H. Hardin, Jan 03 2009

Status

approved