A230727 - OEIS

%I #8 Sep 22 2018 11:51:10

%S 0,8,260,9760,389148,15237056,597115044,23414415888,917986434396,

%T 35990833477072,1411075267502276,55323263878390080,

%U 2169029334553784412,85039966968695574688,3334116217958488966052,130718900222071304691248

%N 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.

%H R. H. Hardin, <a href="/A230727/b230727.txt">Table of n, a(n) for n = 1..210</a>

%F 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.

%F 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

%e Some solutions for n=4:

%e ..0..1..0..5..0....0..1..2..3..4....0..1..2..3..4....0..1..2..3..2

%e ..2..3..4..1..0....0..1..0..5..4....0..1..4..5..0....0..5..4..3..2

%e ..2..1..2..5..2....0..5..2..3..2....0..3..2..1..0....4..0..5..4..3

%e ..0..3..4..3..2....4..5..0..1..0....2..5..0..5..4....1..2..3..2..1

%Y Column 5 of A230730.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 28 2013