A153930 Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with no more than 4 ones in any 3 X 3 X 3 subtriangle.

1, 2, 4, 13, 45, 293, 1880, 22810, 274047, 6160861, 137419960, 5755708030, 238764714329, 18607726818765, 1436358552064865, 208215628095796834, 29898827223053355535, 8063377147636346175953, 2154023814255202610544411

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Crossrefs

Sequence in context: A337797 A300931 A286074 * A284107 A184177 A005164

Adjacent sequences: A153927 A153928 A153929 * A153931 A153932 A153933

Keyword

nonn

Author

R. H. Hardin, Jan 03 2009

Status

approved