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A146066
Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.
0
1, 1, 1, 1, 3, 9, 19, 69, 389, 2287, 15081, 141721, 1694175, 23795099, 418616469, 9434924199, 264113682081, 9153093458787, 397472720900369, 21616544571284115, 1466493314737915869, 124160358455186794957
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.0.0.1.1.0.1.1.0
.0.0.0.1.0.0.1.0
.1.0.0.1.1.0.1.1
.1.1.1.0.0.1.0.0
.0.0.1.0.0.1.1.1
.1.0.0.1.1.0.0.1
.1.1.1.0.1.0.0.0
.0.0.1.0.1.1.0.0
CROSSREFS
Sequence in context: A147070 A130586 A147146 * A164283 A375231 A178963
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved