A162114 Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in strictly increasing order, and no more than 6 ones in any row or column

2, 4, 9, 56, 499, 8000, 200367, 7707352, 406328329, 28320262170, 2490234078408, 267515727878427

Offset

1,1

Links

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

Crossrefs

Sequence in context: A241600 A162112 A162113 * A162115 A162116 A162117

Adjacent sequences: A162111 A162112 A162113 * A162115 A162116 A162117

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved