A147451 - OEIS

A147451

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 11000-01100-00110-00011 pattern in any orientation.

1, 1, 1, 1, 1, 5, 13, 25, 101, 375, 1753, 9905, 61267, 438109, 3882461, 41001981, 504280659

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OFFSET

1,6

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.0.0.0

.1.0.0.0.0.0.0.0

.1.1.0.0.1.0.0.0

.0.1.1.0.1.1.0.0

.0.0.1.1.0.1.1.0

.0.0.0.1.0.0.1.1

.0.0.0.0.0.0.0.1

.0.0.0.0.0.0.0.0

CROSSREFS

Sequence in context: A098480 A018394 A309383 * A173979 A190446 A188471

Adjacent sequences: A147448 A147449 A147450 * A147452 A147453 A147454

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved