A228790 Number of n X n binary arrays with top left element equal to 1 and no two ones adjacent horizontally or nw-se.

1, 2, 36, 586, 37944, 3835792, 1104367784, 619684261316, 861640042953968, 2553753667566404176, 17730379458709838261420, 271886420146092794204826516, 9552041362065797908250895398960, 751574042423604397352344101718881740

Offset

1,2

Comments

Diagonal of A228796

Links

R. H. Hardin, Table of n, a(n) for n = 1..29

Example

Some solutions for n=4
..1..0..0..0....1..0..0..1....1..0..0..0....1..0..0..0....1..0..0..1
..1..0..0..1....1..0..0..1....1..0..1..0....0..0..0..0....0..0..1..0
..0..0..0..1....1..0..0..1....0..0..1..0....0..0..0..0....0..0..1..0
..1..0..1..0....0..0..0..0....0..0..1..0....1..0..0..0....0..0..0..0

Crossrefs

Sequence in context: A141132 A064030 A367982 * A124104 A262973 A207832

Adjacent sequences: A228787 A228788 A228789 * A228791 A228792 A228793

Keyword

nonn

Author

R. H. Hardin Sep 04 2013

Status

approved