A269029 Number of n X n 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

0, 24, 348, 18384, 1326576, 208867428, 63310818360, 40013955378312, 51911512873697772, 140039775591497709312, 791864652110724378938904, 9334169232033820587188999592, 232675011644185023762453520339476

Offset

1,2

Comments

Diagonal of A269035.

Links

R. H. Hardin, Table of n, a(n) for n = 1..14

Example

Some solutions for n=4
..2..2..2..2. .2..1..0..0. .2..1..0..2. .2..1..2..2. .0..1..2..1
..2..2..2..1. .0..0..0..0. .0..1..2..1. .0..1..2..1. .2..1..0..2
..1..2..2..1. .0..0..0..0. .2..1..0..1. .0..1..2..1. .0..1..2..1
..2..1..2..1. .1..0..0..0. .2..1..2..1. .2..2..2..2. .0..1..2..2

Crossrefs

Cf. A269035.

Sequence in context: A056634 A022748 A288968 * A004325 A075621 A293618

Adjacent sequences: A269026 A269027 A269028 * A269030 A269031 A269032

Keyword

nonn

Author

R. H. Hardin, Feb 18 2016

Status

approved