login
A146928
Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1111-1001 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 3, 7, 13, 26, 70, 233, 869, 3436, 14680, 71757, 413520, 2721699, 19996282, 163378650, 1508376980, 15870814986, 189905190363, 2566140210269, 39033535389467, 670295254576489, 13033170011033515, 287051699463343610
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.1.0.0.1
.0.0.0.0.1.1.1.1
.0.0.0.0.1.0.0.1
.0.1.1.1.0.0.0.0
.0.0.1.0.0.0.0.0
.0.0.1.0.0.0.0.0
.0.1.1.1.0.0.0.0
CROSSREFS
Sequence in context: A284297 A205521 A125898 * A068673 A298360 A140465
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved