A162058 Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in nondecreasing order, and no more than 3 ones in any row or column

2, 6, 18, 77, 363, 2049, 12734, 88165, 657807, 5333430, 46068228, 424836442, 4143278352, 42649790768, 461486812345, 5232359427722, 62011437997666

Offset

1,1

Links

Table of n, a(n) for n=1..17.

Crossrefs

Sequence in context: A007116 A280763 A079391 * A113844 A266858 A141580

Adjacent sequences: A162055 A162056 A162057 * A162059 A162060 A162061

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved