A268804 Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

24, 104, 332, 1202, 4158, 14308, 48460, 162722, 541744, 1791504, 5889586, 19264864, 62738690, 203528858, 658003018, 2120809106, 6816832928, 21856821554, 69922091542, 223229394256, 711333766468, 2262803472594, 7186710244256

Offset

1,1

Comments

Column 3 of A268809.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-2) -2*a(n-3) -33*a(n-4) -42*a(n-5) -14*a(n-6) +10*a(n-7) +8*a(n-8) -a(n-10) for n>12

Example

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

Crossrefs

Cf. A268809.

Sequence in context: A182675 A100155 A304415 * A186932 A275506 A185743

Adjacent sequences: A268801 A268802 A268803 * A268805 A268806 A268807

Keyword

nonn

Author

R. H. Hardin, Feb 13 2016

Status

approved