A181265 Number of n X n binary matrices M with rows in strictly increasing order and rows of M*Mtranspose (mod 2) in strictly increasing order.

2, 2, 6, 111, 2607, 256746, 63961223, 49499166213

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Example

M and M*Mtranspose (mod 2) for 4X4
..0..1..1..0......0..0..1..1
..1..0..0..0......0..1..1..1
..1..0..1..0......1..1..0..0
..1..0..1..1......1..1..0..1

Crossrefs

Diagonal of A181266.

Sequence in context: A303225 A326943 A304564 * A382666 A093909 A114362

Adjacent sequences: A181262 A181263 A181264 * A181266 A181267 A181268

Keyword

nonn,more

Author

R. H. Hardin, Oct 10 2010

Status

approved