A147464 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 21, 43, 107, 271, 771

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.1.1.0.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.1.1
.0.1.1.0.0.0.0.1.1
.0.1.1.0.0.0.1.1.0
.1.1.0.0.0.0.1.1.0
.1.1.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A146377 A147501 A147335 * A146058 A155354 A136219

Adjacent sequences: A147461 A147462 A147463 * A147465 A147466 A147467

Keyword

nonn

Author

R. H. Hardin

Status

approved