A147287 - OEIS

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A147287

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0111-0001-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 25, 41, 113, 265, 1045, 2597, 10607, 34895, 213407, 913033, 6860785, 33581603

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

OFFSET

1,9

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

Maximal 9 X 9 example

.1.0.0.0.0.0.0.1.1

.1.1.0.0.0.1.1.1.0

.0.1.0.0.0.1.0.0.0

.0.1.1.1.0.1.0.0.0

.0.0.0.0.0.0.0.0.0

.0.0.0.1.0.1.1.1.0

.0.0.0.1.0.0.0.1.0

.0.1.1.1.0.0.0.1.1

.1.1.0.0.0.0.0.0.1

CROSSREFS

Sequence in context: A242074 A366428 A195564 * A240758 A031331 A236838

Adjacent sequences: A147284 A147285 A147286 * A147288 A147289 A147290

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved