A147432 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1010-1111-0101 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 21, 39, 91, 251, 693, 2197, 6837, 23871, 89603, 379705, 1672695, 8302957, 42265243, 244734851, 1469763313

Offset

1,9

Links

Table of n, a(n) for n=1..26.

Example

Maximal 9 X 9 example
.0.0.0.0.1.0.1.0.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.0.1.0.1.1
.0.1.1.0.0.0.1.1.0
.1.1.0.0.0.0.0.1.1
.0.1.1.0.0.0.1.1.0
.1.1.0.1.0.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.0.1.0.1.0.0.0.0

Crossrefs

Sequence in context: A032606 A098482 A342422 * A018367 A146369 A146377

Adjacent sequences: A147429 A147430 A147431 * A147433 A147434 A147435

Keyword

nonn

Author

R. H. Hardin

Status

approved