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A146019
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 2X4 el 1,1 1,2 1,3 1,4 2,4 with any orientation.
0
1, 1, 1, 1, 1, 1, 3, 7, 15, 29, 61, 211, 895, 3955, 16593, 80999, 462679, 3239573, 25414255, 222500583, 2101470837, 23313975471, 290908388247, 4246548210105, 68354920234083
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.0.0.0.0.1.0.0
.0.0.1.1.1.1.0.0
.0.1.0.0.0.0.1.1
.0.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.0
.0.0.1.1.1.1.0.0
.0.0.1.0.0.0.0.0
CROSSREFS
Sequence in context: A284022 A327554 A120538 * A284421 A283864 A283606
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved