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A146606 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0001 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 23, 55, 135, 381, 1155, 4259, 15095, 63361, 271287, 1364019, 7046127, 42849769, 267209541, 1961120087, 14636956303, 129172123843, 1159685046407, 12305875469689 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..29.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.0.0.1.0.0

.0.0.0.1.1.1.1.0.0

.0.0.0.1.0.0.0.1.1

.0.1.1.0.0.0.0.1.0

.0.1.0.0.0.0.0.1.0

.0.1.0.0.0.0.1.1.0

.1.1.0.0.0.1.0.0.0

.0.0.1.1.1.1.0.0.0

.0.0.1.0.0.0.0.0.0

CROSSREFS

Sequence in context: A297953 A084898 A147380 * A101302 A102948 A232533

Adjacent sequences:  A146603 A146604 A146605 * A146607 A146608 A146609

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified May 29 15:44 EDT 2020. Contains 334704 sequences. (Running on oeis4.)