A147371 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0111-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 3, 9, 19, 42, 149, 642, 3217, 16918, 103595, 764774, 6743975, 68369223, 809162389, 11357687762, 186710566988, 3547308633892, 78610913689329, 2049663760103557, 62999437730030008

Offset

1,6

Links

Table of n, a(n) for n=1..24.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.1.1.1.0
.0.0.0.0.0.0.1.1
.0.0.0.0.1.1.1.0
.0.1.0.1.0.0.0.0
.0.1.0.1.0.0.0.0
.0.1.1.1.0.0.0.0
.0.0.1.0.0.0.0.0

Crossrefs

Sequence in context: A145947 A153084 A285927 * A075188 A051894 A146393

Adjacent sequences: A147368 A147369 A147370 * A147372 A147373 A147374

Keyword

nonn

Author

R. H. Hardin

Status

approved