A147154 - OEIS

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A147154

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1100-0111-0010 pattern in any orientation.

0

1, 1, 1, 1, 1, 9, 33, 125, 685, 3853, 28603, 231163, 2799935, 41066873, 767865147, 16399923305

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

OFFSET

1,6

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

Maximal 8 X 8 example

.0.0.1.1.0.0.1.0

.0.1.1.0.0.0.1.1

.1.1.0.0.0.1.1.0

.0.1.0.0.1.1.0.0

.0.0.1.1.0.0.1.0

.0.1.1.0.0.0.1.1

.1.1.0.0.0.1.1.0

.0.1.0.0.1.1.0.0

CROSSREFS

Sequence in context: A146180 A221447 A147147 * A257284 A257744 A147275

Adjacent sequences: A147151 A147152 A147153 * A147155 A147156 A147157

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved