A162115 Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in strictly increasing order, and no more than 7 ones in any row or column

2, 4, 9, 56, 499, 8000, 207554, 9186901, 646499724, 67812031124, 9964922040226, 1948175255901120

Offset

1,1

Links

Table of n, a(n) for n=1..12.

Crossrefs

Sequence in context: A162112 A162113 A162114 * A162116 A162117 A162109

Adjacent sequences: A162112 A162113 A162114 * A162116 A162117 A162118

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved