A147215 - OEIS

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A147215

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0111-0011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 17, 41, 71, 215, 773, 2523, 9517, 44347, 255961, 1482711, 8989887, 64060215, 492775957, 4232478379

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

OFFSET

1,8

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.1.1.0

.1.0.0.1.1.1.0.0

.1.1.0.1.1.0.0.0

.0.1.1.0.0.1.1.0

.0.0.0.1.1.0.1.1

.0.0.1.1.1.0.0.1

.0.1.1.0.0.0.0.0

CROSSREFS

Sequence in context: A350052 A078655 A052279 * A126790 A089200 A332227

Adjacent sequences: A147212 A147213 A147214 * A147216 A147217 A147218

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved