A162052 Number of n X n symmetric binary arrays with rows, considered as binary numbers, in nondecreasing order, and an even number of ones in each row.

1, 2, 3, 8, 31, 188, 2150, 40946, 1490523, 95741796, 11466071450, 2488266955088, 1000177563819104, 739901172499913695, 1017435042973995016499

Offset

1,2

Links

Table of n, a(n) for n=1..15.

Crossrefs

Sequence in context: A160586 A340935 A162074 * A082569 A340495 A084908

Adjacent sequences: A162049 A162050 A162051 * A162053 A162054 A162055

Keyword

nonn

Author

R. H. Hardin, Jun 25 2009

Status

approved