A268632 - OEIS

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

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

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