A162117 Number of n X n symmetric binary arrays with rows, considered as graycode numbers, in strictly increasing order, and no more than 9 ones in any row or column

2, 4, 9, 56, 499, 8000, 207554, 9382078, 732814910, 100881440613, 23970739627607, 9428485931810668

Offset

1,1

Links

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

Crossrefs

Sequence in context: A162114 A162115 A162116 * A162109 A271553 A067603

Adjacent sequences: A162114 A162115 A162116 * A162118 A162119 A162120

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved