A153965 Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 9 ones in any 4 X 4 X 4 subtriangle.

1, 2, 2, 4, 15, 31, 126, 927, 3933, 31429, 472959, 4005742, 63878219, 1917687587, 32433255622, 1032580394091, 61890749905798, 2090664356692297, 132950076813594995, 15915454829832076325, 1073793991171675728498

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Crossrefs

Sequence in context: A268423 A261531 A153968 * A121221 A122598 A279069

Adjacent sequences: A153962 A153963 A153964 * A153966 A153967 A153968

Keyword

nonn

Author

R. H. Hardin Jan 03 2009

Status

approved