A180996 Number of n X n binary matrices with rows and columns each in strictly increasing order as binary numbers and no 1 neighboring another 1

2, 2, 3, 7, 26, 145, 1269, 16666, 336209, 10197321, 469338906, 32492055785, 3394528588557, 533338846061070, 126158953592584561, 44869991848754725313, 24002894812644474337158, 19303006356138543308410109

Offset

1,1

Comments

Diagonal of A180997

Links

R. H. Hardin, Table of n, a(n) for n=1..24

Example

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

Crossrefs

Sequence in context: A185387 A038507 A077001 * A307503 A087522 A092970

Adjacent sequences: A180993 A180994 A180995 * A180997 A180998 A180999

Keyword

nonn

Author

R. H. Hardin Sep 30 2010

Status

approved