A146007 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.

1, 1, 3, 1, 7, 1, 130, 91, 6332, 1793, 406187, 49449, 61263393, 8852445, 32470148409, 4239917884, 39617903461163, 3145168364391, 99051976325369286, 5582755445095006, 631563332322873981680, 29889178997259704973

Offset

1,3

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.1.0.0.0.0.0.0.1
.1.1.1.0.0.1.1.1
.1.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.1
.1.1.1.0.0.1.1.1
.1.0.0.0.0.0.0.1

Crossrefs

Sequence in context: A146281 A146265 A146217 * A061782 A074625 A284877

Adjacent sequences: A146004 A146005 A146006 * A146008 A146009 A146010

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved