A147478 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-1100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 4, 7, 14, 21, 38, 89, 317, 871

Offset

1,9

Links

Table of n, a(n) for n=1..16.

Example

Maximal 9 X 9 example
.0.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.1.0.0.1.1.0.0.0
.0.1.0.0.0.0.1.1.1
.1.1.1.0.0.0.1.1.1
.1.1.1.0.0.0.0.1.0
.0.0.0.1.1.0.0.1.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A338551 A188319 A171378 * A147372 A201272 A147440

Adjacent sequences: A147475 A147476 A147477 * A147479 A147480 A147481

Keyword

nonn

Author

R. H. Hardin

Status

approved