A154002 Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 13 ones in any 5 X 5 X 5 subtriangle.

1, 2, 2, 4, 8, 15, 30, 121, 231, 922, 3737, 14596, 58211, 469831, 1835827, 14554240, 117947573, 917117580, 7292920219, 117680064956, 918073021793, 14535229309434, 235458669342831, 3657602835082750, 58133874029508411, 1875022386576869767

Offset

0,2

Links

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

Crossrefs

Sequence in context: A098788 A190820 A153999 * A154005 A222386 A222935

Adjacent sequences: A153999 A154000 A154001 * A154003 A154004 A154005

Keyword

nonn

Author

R. H. Hardin, Jan 04 2009

Status

approved