A140178 Half the number of n X n symmetric binary matrices with adjacent rows differing in at most three positions.

1, 4, 32, 427, 7396, 130612, 2097152, 30417025, 409957616, 5282779354

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Crossrefs

Sequence in context: A298694 A222685 A322735 * A366685 A088991 A009668

Adjacent sequences: A140175 A140176 A140177 * A140179 A140180 A140181

Keyword

nonn

Author

R. H. Hardin, Jun 15 2008

Status

approved