A147372 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0111-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 4, 7, 14, 21, 40, 79, 252, 611, 2359, 6199, 23158, 70484, 325136, 1222235, 6869095, 29506240, 189032773, 936666179

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.1.1.0.0.0
.1.1.1.0.1.0.1.1.1
.0.0.1.1.0.1.1.0.0
.1.1.1.0.1.0.1.1.1
.0.0.0.1.1.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A188319 A171378 A147478 * A201272 A147440 A146678

Adjacent sequences: A147369 A147370 A147371 * A147373 A147374 A147375

Keyword

nonn

Author

R. H. Hardin

Status

approved