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A146574
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-0100-1111 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 3, 5, 11, 21, 43, 131, 425, 1453, 5677, 20565, 100203, 517949, 3251987, 21002085, 153166855, 1157817079, 10741996431, 104706915655
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.0.0.1.1.1.1.0
.0.0.0.0.1.0.0.1
.0.0.0.0.1.0.0.1
.1.0.0.0.0.1.1.1
.1.1.1.0.0.0.0.1
.1.0.0.1.0.0.0.0
.1.0.0.1.0.0.0.0
.0.1.1.1.1.0.0.0
CROSSREFS
Sequence in context: A077465 A283647 A283905 * A007873 A274938 A283603
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved