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A146926 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1001-1111-1001 pattern in any orientation. 0
1, 1, 1, 3, 3, 5, 9, 17, 89, 140, 1134, 2523, 20495, 73514, 534008, 1996987, 23508472, 92663083, 1862869380, 7762461636, 266742576438, 1312733745392, 59491047519251, 367850100364195, 19425750984998415, 144916187683650857 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..26.

EXAMPLE

Maximal 8 X 8 example

.1.1.1.0.0.1.1.1

.0.1.0.0.0.0.1.0

.0.1.0.0.0.0.1.0

.1.1.1.0.0.1.1.1

.0.0.0.0.0.0.0.0

.0.0.1.0.0.1.0.0

.0.0.1.1.1.1.0.0

.0.0.1.0.0.1.0.0

CROSSREFS

Sequence in context: A325187 A209083 A137202 * A000198 A202674 A027170

Adjacent sequences:  A146923 A146924 A146925 * A146927 A146928 A146929

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified December 13 12:45 EST 2019. Contains 329968 sequences. (Running on oeis4.)