A180999 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 odd number of 1s

1, 1, 1, 3, 21, 613, 58894, 17001258, 14824281524, 39871721434052

Offset

1,4

Comments

Diagonal of A181000

Links

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

Example

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

Crossrefs

Sequence in context: A128679 A292331 A111432 * A181003 A093549 A012044

Adjacent sequences: A180996 A180997 A180998 * A181000 A181001 A181002

Keyword

nonn

Author

R. H. Hardin Sep 30 2010

Status

approved