A181272 Number of 4 X n binary matrices M with rows in strictly increasing order and rows of M*transpose(M) (mod 2) in strictly increasing order.

0, 0, 4, 111, 1793, 32124, 513260, 8397376, 133979600, 2151884352, 34376925632, 550298217984, 8799317537024, 140789221362688, 2252143151246336, 36033204166164480, 576491512426680320, 9223724397701578752

Offset

1,3

Links

R. H. Hardin, Table of n, a(n) for n=1..27

Example

M and M*transpose(M) (mod 2) for 4 X 3:
..0..0..0......0..0..0..0
..0..1..1......0..0..0..1
..1..0..0......0..0..1..1
..1..1..0......0..1..1..0

Crossrefs

Row 4 of A181266.

Sequence in context: A286424 A358806 A358779 * A214107 A202518 A212655

Adjacent sequences: A181269 A181270 A181271 * A181273 A181274 A181275

Keyword

nonn

Author

R. H. Hardin, Oct 10 2010

Status

approved