A146725 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1101-0111 pattern in any orientation.

1, 1, 1, 1, 3, 13, 35, 157, 741, 4435, 44453, 490313, 6256041, 104651895, 2130039209, 56493398929, 1931237117101, 81069750246845, 4246906418006015, 279802247495802441

Offset

1,5

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.0.1.0.0.0.0
.0.0.0.1.1.0.0.0
.1.1.1.0.1.0.1.1
.1.0.1.1.0.0.1.0
.0.0.0.0.0.0.1.1
.0.0.0.1.1.1.0.1
.0.0.0.1.0.1.1.0

Crossrefs

Sequence in context: A108480 A322187 A146741 * A146424 A146049 A061483

Adjacent sequences: A146722 A146723 A146724 * A146726 A146727 A146728

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved