A245866 - OEIS

%I #11 Nov 05 2018 03:05:06

%S 90,318,960,3102,9726,30900,97602,309078,977664,3094038,9789654,

%T 30977796,98020170,310161870,981426624,3105480558,9826505742,

%U 31093507092,98387556594,311322635814,985101990912,3117106968486,9863299264806

%N Number of length n+2 0..5 arrays with some pair in every consecutive three terms totalling exactly 5.

%H R. H. Hardin, <a href="/A245866/b245866.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + 4*a(n-2) - a(n-3).

%F Empirical g.f.: 6*x*(15 + 23*x - 6*x^2) / (1 - 2*x - 4*x^2 + x^3). - _Colin Barker_, Nov 04 2018

%e Some solutions for n=7:

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

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

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

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

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

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

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

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

%e   2   5   2   2   3   1   5   3   4   3   5   3   1   5   2   1

%Y Column 5 of A245869.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 04 2014