A147420 - OEIS

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A147420

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1001-1111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 9, 23, 64, 295, 1072, 4637, 27060, 195073, 1617157, 15822995, 190207942, 2553434864, 40752029560

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

Maximal 8 X 8 example

.0.1.1.0.0.0.0.0

.1.1.1.1.0.1.1.0

.1.0.0.1.0.0.1.1

.0.1.1.0.0.0.1.1

.1.1.0.0.0.1.1.0

.1.1.0.0.1.0.0.1

.0.1.1.0.1.1.1.1

.0.0.0.0.0.1.1.0

CROSSREFS

Sequence in context: A183338 A212676 A211478 * A259170 A057453 A282761

Adjacent sequences: A147417 A147418 A147419 * A147421 A147422 A147423

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved