A147404 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1110-0111-0001 pattern in any orientation.

1, 1, 1, 5, 1, 9, 13, 53, 137, 741, 2493, 19441, 73321, 1016967, 4911015, 87040405, 643897713

Offset

1,4

Links

Table of n, a(n) for n=1..17.

Example

Maximal 8 X 8 example
.1.1.0.0.1.1.0.0
.0.1.1.0.0.1.1.0
.0.1.1.0.0.1.1.0
.0.0.1.1.0.0.1.1
.1.1.0.0.1.1.0.0
.0.1.1.0.0.1.1.0
.0.1.1.0.0.1.1.0
.0.0.1.1.0.0.1.1

Crossrefs

Sequence in context: A134233 A100542 A324378 * A254068 A146070 A308504

Adjacent sequences: A147401 A147402 A147403 * A147405 A147406 A147407

Keyword

nonn

Author

R. H. Hardin

Status

approved