cp's OEIS Frontend

A243601 Number of length n+2 0..4 arrays with no three elements in a row with pattern aba (with a!=b) and new values 0..4 introduced in 0..4 order.

%I A243601 #8 Nov 02 2018 12:29:52
%S A243601 4,10,29,96,349,1350,5425,22297,92841,389456,1640630,6927937,29294645,
%T A243601 123967625,524830618,2222483751,9412820990,39869076285,168877805414,
%U A243601 715352976032,3030223762722,12836088840031,54374194848619
%N A243601 Number of length n+2 0..4 arrays with no three elements in a row with pattern aba (with a!=b) and new values 0..4 introduced in 0..4 order.
%H A243601 R. H. Hardin, <a href="/A243601/b243601.txt">Table of n, a(n) for n = 1..210</a>
%F A243601 Empirical: a(n) = 8*a(n-1) - 18*a(n-2) + 5*a(n-3) + 17*a(n-4) - 4*a(n-5) - 6*a(n-6) - a(n-7).
%F A243601 Empirical g.f.: x*(4 - 22*x + 21*x^2 + 24*x^3 - 15*x^4 - 13*x^5 - 2*x^6) / ((1 - x)*(1 - x - x^2)*(1 - 2*x - x^2)*(1 - 4*x - x^2)). - _Colin Barker_, Nov 02 2018
%e A243601 Some solutions for n=5:
%e A243601 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e A243601 ..1....1....0....1....1....1....1....1....1....1....1....1....1....1....1....1
%e A243601 ..1....2....1....2....2....1....1....2....1....2....2....2....2....2....2....2
%e A243601 ..1....3....1....3....3....2....2....0....0....3....3....3....3....3....3....2
%e A243601 ..2....1....0....3....1....2....3....3....2....1....1....1....0....3....0....3
%e A243601 ..3....2....2....0....2....1....0....3....3....1....4....4....0....3....1....3
%e A243601 ..1....3....2....2....4....3....2....3....4....1....2....4....2....4....3....2
%Y A243601 Column 4 of A243607.
%K A243601 nonn
%O A243601 1,1
%A A243601 _R. H. Hardin_, Jun 07 2014