cp's OEIS Frontend

A222919 Number of n X 1 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.

%I A222919 #8 Mar 16 2018 06:25:42
%S A222919 1,2,4,12,41,158,663,2944,13537,63551,301968,1444795,6940099,33411718,
%T A222919 161058633,776930015,3749357128,18098055047,87370273487,421820387606,
%U A222919 2036618058597,9833358788859,47478828272736,229245800095323
%N A222919 Number of n X 1 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.
%C A222919 Column 1 of A222924.
%H A222919 R. H. Hardin, <a href="/A222919/b222919.txt">Table of n, a(n) for n = 1..210</a>
%F A222919 Empirical: a(n) = 7*a(n-1) - 7*a(n-2) - 20*a(n-3) + 10*a(n-4) + 24*a(n-5) + 8*a(n-6) for n>8.
%F A222919 Empirical g.f.: x*(1 + x)*(1 - 6*x + 3*x^2 + 15*x^3 - 9*x^5 - 3*x^6) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 4*x - 4*x^2)). - _Colin Barker_, Mar 16 2018
%e A222919 All solutions for n=3:
%e A222919 ..0....0....0....0
%e A222919 ..1....1....1....0
%e A222919 ..2....1....0....1
%Y A222919 Cf. A222924.
%K A222919 nonn
%O A222919 1,2
%A A222919 _R. H. Hardin_, Mar 09 2013