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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.
0
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
CROSSREFS
Sequence in context: A083698 A128976 A199627 * A318205 A046772 A348291
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 03 2009
STATUS
approved