A147142 - OEIS

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A147142

Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.

1, 1, 1, 3, 7, 17, 39, 127, 681, 3913, 21369, 147701, 1344439, 15252227, 199338371, 3018576265, 55990200331, 1283966558111, 35424143775231

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

OFFSET

1,4

LINKS

Table of n, a(n) for n=1..19.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.1.1.0.0

.0.0.0.0.0.1.1.0

.0.0.0.0.0.0.1.1

.0.0.0.0.1.1.0.1

.1.0.0.1.0.1.1.0

.1.1.0.1.1.0.1.1

.0.1.1.0.1.1.0.1

.0.0.1.1.0.1.1.0

CROSSREFS

Sequence in context: A229514 A077927 A005197 * A298371 A367396 A106472

Adjacent sequences: A147139 A147140 A147141 * A147143 A147144 A147145

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved