A147458 - OEIS

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A147458

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 11000-01111-11000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 9, 21, 34, 61, 142, 363, 998, 3151, 10096, 34473, 121095, 493961, 2091176, 9966879, 48888970, 265507652

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

OFFSET

1,8

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.1.1.0.1.0

.1.1.1.1.0.0.1.0

.0.0.0.1.1.0.1.0

.1.0.1.0.0.1.1.1

.1.1.1.0.0.1.0.1

.0.1.0.1.1.0.0.0

.0.1.0.0.1.1.1.1

.0.1.0.1.1.0.0.0

CROSSREFS

Sequence in context: A286590 A061978 A031886 * A169927 A287057 A048780

Adjacent sequences: A147455 A147456 A147457 * A147459 A147460 A147461

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved