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A140177
Half the number of n X n symmetric binary matrices with adjacent rows differing in at most two positions.
0
1, 4, 25, 171, 1024, 5452, 27319, 133343, 650240, 3183136, 15730003, 78792479, 401274724
OFFSET
1,2
CROSSREFS
Sequence in context: A081068 A163072 A278689 * A034494 A084210 A093683
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 15 2008
STATUS
approved