A147105 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 13, 21, 51, 105, 313, 705, 2345, 6341, 26177, 91001, 474255, 1837677, 10745995, 49191077, 334389565, 1781473499

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.0.0
.0.0.1.1.0.0.0.0
.1.0.1.0.1.1.1.0
.1.0.1.0.0.0.1.1
.1.1.0.0.0.1.0.1
.0.1.1.1.0.1.0.1
.0.0.0.0.1.1.0.0
.0.0.1.1.1.0.0.0

Crossrefs

Sequence in context: A243162 A147351 A147097 * A258774 A057589 A299645

Adjacent sequences: A147102 A147103 A147104 * A147106 A147107 A147108

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved