A147171 - OEIS

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A147171

Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 193, 369, 2595, 6071, 68113, 166829, 3392025, 10054713, 1656174053, 6422563367, 1047960128407, 4842120420549, 791850842457727

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

OFFSET

1,9

LINKS

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

EXAMPLE

Maximal 9 X 9 example

.0.0.0.1.0.1.0.0.0

.1.1.1.1.0.1.1.1.1

.0.1.0.0.0.0.0.1.0

.0.0.0.0.0.0.0.0.0

.1.0.0.0.0.0.0.0.1

.1.1.1.1.0.1.1.1.1

.0.0.1.0.0.0.1.0.0

CROSSREFS

Sequence in context: A216451 A139506 A342308 * A146824 A256348 A142453

Adjacent sequences: A147168 A147169 A147170 * A147172 A147173 A147174

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved