A268907 Number of 4Xn 0..2 arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

0, 1344, 12960, 118584, 1004184, 8250912, 66210264, 522241560, 4063962024, 31282792704, 238663638432, 1807307152056, 13599932970888, 101786388133320, 758232651966984, 5625079743143376, 41579318178922608, 306353541215271960

Offset

1,2

Comments

Row 4 of A268904.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 18*a(n-1) -111*a(n-2) +282*a(n-3) -333*a(n-4) +180*a(n-5) -36*a(n-6) for n>12

Example

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

Crossrefs

Cf. A268904.

Sequence in context: A259675 A205820 A202430 * A206321 A230974 A239192

Adjacent sequences: A268904 A268905 A268906 * A268908 A268909 A268910

Keyword

nonn

Author

R. H. Hardin, Feb 15 2016

Status

approved