A269762 Number of n X 3 0..5 arrays with some element plus some horizontally or vertically adjacent neighbor totalling five exactly once.

60, 17520, 2624640, 326697720, 37212131520, 4022791852800, 420141188848320, 42818890099881480, 4284894917784397440, 422758967764941655440, 41241625930544770099200, 3986294332446031676572440

Offset

1,1

Links

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

Formula

Empirical: a(n) = 184*a(n-1) - 9134*a(n-2) + 61640*a(n-3) - 112225*a(n-4) for n>5.

Empirical g.f.: 60*x*(1 + 108*x - 850*x^2 + 1554*x^3 + 225*x^4) / (1 - 92*x + 335*x^2)^2. - Colin Barker, Jan 28 2019

Example

Some solutions for n=2:
..1..2..5. .0..1..4. .4..0..2. .2..4..4. .0..0..4. .5..3..0. .2..0..4
..5..4..1. .2..0..4. .3..0..5. .2..1..5. .4..1..5. .2..1..4. .1..2..1

Crossrefs

Column 3 of A269767.

Sequence in context: A295598 A113424 A009564 * A291912 A001460 A003794

Adjacent sequences: A269759 A269760 A269761 * A269763 A269764 A269765

Keyword

nonn

Author

R. H. Hardin, Mar 04 2016

Status

approved