A140177 Half the number of n X n symmetric binary matrices with adjacent rows differing in at most two positions.

1, 4, 25, 171, 1024, 5452, 27319, 133343, 650240, 3183136, 15730003, 78792479, 401274724

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Crossrefs

Sequence in context: A081068 A163072 A278689 * A034494 A084210 A093683

Adjacent sequences: A140174 A140175 A140176 * A140178 A140179 A140180

Keyword

nonn

Author

R. H. Hardin, Jun 15 2008

Status

approved