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A146042 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 2X4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation. 0
1, 1, 1, 1, 1, 3, 5, 11, 21, 41, 165, 701, 2953, 12345, 51325, 344201, 2572877, 21631323, 180106811, 1718811817, 19639803327, 281005626019, 4302161174593, 75232261306781, 1397819874484453, 32083258430460691 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.0.0.0

.0.0.1.1.1.1.0.0

.0.1.0.0.1.0.1.0

.0.1.0.0.0.1.1.0

.0.1.1.0.0.0.1.0

.0.1.0.1.0.0.1.0

.0.0.1.1.1.1.0.0

.0.0.0.0.0.0.0.0

CROSSREFS

Sequence in context: A147243 A192664 A122997 * A291219 A284358 A283584

Adjacent sequences:  A146039 A146040 A146041 * A146043 A146044 A146045

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved

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Last modified September 24 12:20 EDT 2020. Contains 337318 sequences. (Running on oeis4.)