A181006 Number of (n+2)xn 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

0, 0, 0, 0, 123, 16675, 5752742, 5565513638, 15996779979401, 141854932507575253

Offset

1,5

Comments

Subdiagonal 2 of A181004

Links

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

Example

Some solutions for 7X5
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..1..1....0..0..0..1..1....0..0..0..1..1....0..0..0..1..1
..0..0..1..0..1....0..0..1..0..1....0..0..1..0..1....0..0..1..0..1
..0..0..1..1..0....0..0..1..1..0....0..0..1..1..0....0..0..1..1..0
..0..1..0..1..0....0..1..0..1..0....0..1..1..0..0....0..1..1..0..0
..1..0..0..1..0....1..0..1..0..0....1..0..0..1..0....1..0..1..0..0
..1..1..0..0..0....1..1..1..1..0....1..1..1..1..0....1..1..0..0..0

Crossrefs

Sequence in context: A095761 A121917 A049670 * A362497 A289331 A334181

Adjacent sequences: A181003 A181004 A181005 * A181007 A181008 A181009

Keyword

nonn

Author

R. H. Hardin Sep 30 2010

Status

approved