A153922 Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 3 ones in any 3 X 3 X 3 subtriangle.

1, 2, 2, 3, 4, 8, 13, 36, 59, 160, 431, 1207, 3281, 14493, 40909, 190825, 830228, 4020596, 18120315, 138139135, 645018986, 5068850751, 37171002203, 301985114648, 2294433300268, 29211683338424, 229716243590382

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Crossrefs

Sequence in context: A320009 A147558 A032243 * A153943 A361117 A049309

Adjacent sequences: A153919 A153920 A153921 * A153923 A153924 A153925

Keyword

nonn

Author

R. H. Hardin, Jan 03 2009

Status

approved