A147031 - OEIS

A147031

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 5, 13, 25, 43, 89, 283, 1197, 5015, 19569, 70793, 320835, 1805563, 12416113, 87073927

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OFFSET

1,9

LINKS

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

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.1.0.0.0.0

.0.0.1.1.1.0.0.0.0

.0.1.0.0.1.1.0.0.0

.0.1.0.0.1.0.1.0.0

.1.1.1.1.0.1.1.1.1

.0.0.1.0.1.0.0.1.0

.0.0.0.1.1.0.0.1.0

.0.0.0.0.1.1.1.0.0

.0.0.0.0.1.0.0.0.0

CROSSREFS

Sequence in context: A240001 A301685 A102724 * A147220 A269713 A196069

Adjacent sequences: A147028 A147029 A147030 * A147032 A147033 A147034

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved