A228749 - OEIS

A228749

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

1, 3, 39, 780, 43862, 4823826, 1316714732, 762713002760, 1040109467257908, 3118624187066762728, 21501868781585259257676, 331091404725670052219822756, 11603262095526618070600084170304, 914315533886530112431287075923892544

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Diagonal of A228754

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..30

EXAMPLE

Some solutions for n=4

..1..0..0..0....1..0..0..1....1..0..0..0....1..0..1..0....1..0..0..0

..1..0..0..0....0..1..0..0....0..0..0..1....0..0..1..0....1..0..1..0

..0..1..0..1....0..0..0..1....0..1..0..0....1..0..0..1....1..0..1..0

..0..1..0..0....1..0..0..0....0..1..0..1....0..0..0..0....1..0..0..0

CROSSREFS

Sequence in context: A328809 A327603 A336540 * A370327 A104209 A121247

Adjacent sequences: A228746 A228747 A228748 * A228750 A228751 A228752

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 02 2013

STATUS

approved