A146870 - OEIS

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A146870

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1101-1111 pattern in any orientation.

1, 1, 1, 1, 17, 29, 97, 473, 2981, 21253, 221233, 1979801, 27911349, 414463777, 10310356843, 228677282931, 8215295336657, 272807472524325

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OFFSET

1,5

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

Maximal 8 X 8 example

.1.1.0.0.0.0.0.0

.1.0.0.0.1.1.1.1

.1.1.0.0.1.0.1.1

.1.1.0.0.0.0.0.0

.0.0.0.0.0.0.1.1

.1.1.0.1.0.0.1.1

.1.1.1.1.0.0.0.1

.0.0.0.0.0.0.1.1

CROSSREFS

Sequence in context: A069755 A076727 A347530 * A146744 A103304 A104067

Adjacent sequences: A146867 A146868 A146869 * A146871 A146872 A146873

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved