A230727 Number of n X 5 0..5 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value (x(i,j)+1) mod 6, and upper left element zero.

0, 8, 260, 9760, 389148, 15237056, 597115044, 23414415888, 917986434396, 35990833477072, 1411075267502276, 55323263878390080, 2169029334553784412, 85039966968695574688, 3334116217958488966052, 130718900222071304691248

Offset

1,2

Links

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

Formula

Empirical: a(n) = 37*a(n-1) + 72*a(n-2) + 990*a(n-3) - 16253*a(n-4) - 12331*a(n-5) + 83486*a(n-6) - 56928*a(n-7) for n>8.

Empirical g.f.: 4*x^2*(2 - 9*x - 109*x^2 + 347*x^3 + 2121*x^4 - 3164*x^5 + 540*x^6) / (1 - 37*x - 72*x^2 - 990*x^3 + 16253*x^4 + 12331*x^5 - 83486*x^6 + 56928*x^7). - Colin Barker, Sep 22 2018

Example

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

Crossrefs

Column 5 of A230730.

Sequence in context: A221778 A172127 A230611 * A272392 A162083 A300734

Adjacent sequences: A230724 A230725 A230726 * A230728 A230729 A230730

Keyword

nonn

Author

R. H. Hardin, Oct 28 2013

Status

approved