A230611 Number of n X 5 0..2 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.

0, 8, 260, 7072, 186396, 4899200, 128706852, 3381000336, 88814433756, 2333033998864, 61285601758916, 1609888586400576, 42289561773667932, 1110888696290586976, 29181520062175286564, 766558446366309855152

Offset

1,2

Links

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

Formula

Empirical: a(n) = 31*a(n-1) - 126*a(n-2) + 42*a(n-3) + 79*a(n-4) - a(n-5) + 8*a(n-6) for n>7.

Empirical g.f.: 4*x^2*(2 + 3*x + 5*x^2 - 103*x^3 + 111*x^4 - 2*x^5) / (1 - 31*x + 126*x^2 - 42*x^3 - 79*x^4 + x^5 - 8*x^6). - Colin Barker, Sep 22 2018

Example

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

Crossrefs

Column 5 of A230614.

Sequence in context: A230271 A221778 A172127 * A230727 A272392 A162083

Adjacent sequences: A230608 A230609 A230610 * A230612 A230613 A230614

Keyword

nonn

Author

R. H. Hardin, Oct 25 2013

Status

approved