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A146726
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 3, 7, 15, 27, 51, 141, 615, 2523, 10593, 40853, 196793, 1114237, 8094209, 59485011, 492771709, 4132732207, 42832582765, 478558556527
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.1.1.0.1.0.0.0
.1.0.1.1.1.0.0.0
.1.1.0.0.0.0.0.0
.0.1.0.0.0.0.1.1
.1.1.0.0.0.0.1.0
.0.0.0.0.0.0.1.1
.0.0.0.1.1.1.0.1
.0.0.0.1.0.1.1.0
CROSSREFS
Sequence in context: A146425 A147595 A147127 * A146228 A139806 A143701
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved