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A145796
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only either four adjacent vertically or four adjacent horizontally.
0
1, 1, 1, 3, 9, 16, 93, 367, 2220, 13167, 126326, 1163166, 15908600, 209043350, 4432902382, 88370483688
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OFFSET
1,4
LINKS
Table of n, a(n) for n=1..16.
CROSSREFS
Sequence in context: A197531 A117108 A223188 * A056403 A181349 A240094
Adjacent sequences: A145793 A145794 A145795 * A145797 A145798 A145799
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 19 2008
STATUS
approved

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Last modified February 26 15:25 EST 2025. Contains 381235 sequences.
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