A228500 Number of n X n binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.

1, 1, 12, 87, 2002, 59839, 3862849, 405580157, 81304395949, 28446567810005, 18268841726936268, 20937720031330292269, 43502129718103134992611, 162426195975365708781849519, 1095156092719874995442597502324

Offset

1,3

Comments

Diagonal of A228506

Links

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

Example

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

Crossrefs

Sequence in context: A180797 A137207 A206765 * A348415 A082814 A178257

Adjacent sequences: A228497 A228498 A228499 * A228501 A228502 A228503

Keyword

nonn

Author

R. H. Hardin Aug 23 2013

Status

approved