A268632 Number of n X n 0..2 arrays with some element plus some horizontally or vertically adjacent neighbor totalling two exactly once.

0, 24, 840, 47640, 5419992, 1328460312, 725187096504, 897937832100888, 2550310193527246056, 16737195174968513278656, 255111495114527014241534160, 9064348272085612349020943764248, 752834148761621410865592159869765856

Offset

1,2

Comments

Diagonal of A268639.

Links

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

Example

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

Crossrefs

Cf. A268639.

Sequence in context: A265884 A204559 A078522 * A208792 A195130 A005149

Adjacent sequences: A268629 A268630 A268631 * A268633 A268634 A268635

Keyword

nonn

Author

R. H. Hardin, Feb 09 2016

Status

approved