A147487 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 11011-01110-00100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 4, 7, 13, 21, 47, 71, 266, 697, 2575, 7222, 30644, 93493, 472633, 1837587, 10941522, 49363521, 346195883, 1801870833

Offset

1,7

Links

Table of n, a(n) for n=1..24.

Example

Maximal 8 X 8 example
.1.0.0.1.1.0.1.1
.1.1.0.0.1.1.1.0
.0.1.1.0.0.1.0.0
.1.1.0.0.0.0.0.1
.1.0.0.0.0.0.1.1
.0.0.1.0.0.1.1.0
.0.1.1.1.0.0.1.1
.1.1.0.1.1.0.0.1

Crossrefs

Sequence in context: A100848 A051458 A068940 * A190845 A190805 A008471

Adjacent sequences: A147484 A147485 A147486 * A147488 A147489 A147490

Keyword

nonn

Author

R. H. Hardin

Status

approved