A181003 Number of n X n binary matrices with rows and columns each in strictly increasing order as binary numbers and each row and column having an even number of 1s

1, 0, 1, 3, 21, 632, 58741, 16972746, 14821714373, 39880712826780

Offset

1,4

Comments

Diagonal of A181004

Links

Table of n, a(n) for n=1..10.

Example

All solutions for 4X4
..0..0..0..0....0..0..1..1....0..0..1..1
..0..0..1..1....0..1..0..1....0..1..0..1
..0..1..0..1....1..0..1..0....1..0..0..1
..0..1..1..0....1..1..0..0....1..1..1..1

Crossrefs

Sequence in context: A292331 A111432 A180999 * A093549 A012044 A350513

Adjacent sequences: A181000 A181001 A181002 * A181004 A181005 A181006

Keyword

nonn

Author

R. H. Hardin Sep 30 2010

Status

approved