A234139 - OEIS

A234139

Number of (n+1) X (7+1) 0..3 arrays with every 2 X 2 subblock having the sum of the absolute values of all six edge and diagonal differences equal to 9.

%I #10 Oct 13 2018 09:22:54

%S 9216,9992,11336,14120,19368,30632,53288,104744,214056,481832,1079336,

%T 2667560,6361128,16893992,42139688,117796904,302637096,873644072,

%U 2284036136,6715433000,17725595688,52630822952,139620917288,416680321064

%N Number of (n+1) X (7+1) 0..3 arrays with every 2 X 2 subblock having the sum of the absolute values of all six edge and diagonal differences equal to 9.

%H R. H. Hardin, <a href="/A234139/b234139.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 8*a(n-2) - 30*a(n-3) + 4*a(n-4) + 48*a(n-5) - 32*a(n-6).

%F Empirical g.f.: 8*x*(1152 - 2207*x - 11546*x^2 + 22082*x^3 + 18652*x^4 - 35336*x^5) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 8*x^2)). - _Colin Barker_, Oct 13 2018

%e Some solutions for n=5:

%e 0 3 3 3 1 3 3 0 0 3 3 3 3 0 3 0 2 0 1 3 1 3 1 3

%e 0 0 3 0 1 0 3 3 0 0 3 0 3 3 3 3 2 3 1 0 1 0 1 0

%e 0 3 3 3 1 3 3 0 0 3 3 3 3 0 3 0 2 0 1 3 1 3 1 3

%e 0 0 3 0 1 0 3 3 3 3 0 3 0 0 0 0 2 3 1 0 1 0 1 0

%e 0 3 3 3 1 3 3 0 3 0 0 0 0 3 0 3 2 0 1 3 1 3 1 3

%e 0 0 3 0 1 0 3 3 3 3 0 3 0 0 0 0 2 3 1 0 1 0 1 0

%Y Column 7 of A234140.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 19 2013