cp's OEIS Frontend

A246886 Number of length n+4 0..2 arrays with some pair in every consecutive five terms totalling exactly 2.

%I A246886 #7 Jun 02 2025 10:14:11
%S A246886 231,673,1961,5711,16621,48393,140893,410197,1194243,3476929,10122747,
%T A246886 29471409,85803183,249807769,727291431,2117439451,6164722475,
%U A246886 17947999987,52253885667,152132191293,442918327175,1289514355131,3754297734035
%N A246886 Number of length n+4 0..2 arrays with some pair in every consecutive five terms totalling exactly 2.
%C A246886 Column 2 of A246892
%H A246886 R. H. Hardin, <a href="/A246886/b246886.txt">Table of n, a(n) for n = 1..210</a>
%F A246886 Empirical: a(n) = 2*a(n-1) +2*a(n-2) +a(n-3) +3*a(n-4) -2*a(n-6) -2*a(n-7) -3*a(n-8) -3*a(n-9) +a(n-11) +a(n-13) +a(n-14)
%e A246886 Some solutions for n=6
%e A246886 ..1....1....1....2....0....0....1....2....0....0....1....2....2....1....1....0
%e A246886 ..2....1....2....2....0....1....1....2....2....0....1....1....0....0....0....1
%e A246886 ..2....1....1....1....0....0....2....0....1....2....2....2....1....2....1....1
%e A246886 ..0....1....2....1....2....0....2....0....2....1....2....2....0....1....1....2
%e A246886 ..0....2....1....2....0....2....0....1....2....1....1....1....0....2....0....0
%e A246886 ..0....1....2....2....0....1....1....2....0....1....1....1....1....1....0....2
%e A246886 ..1....2....0....2....2....0....0....2....2....0....2....0....1....2....2....0
%e A246886 ..2....1....2....0....1....2....1....0....0....2....0....0....0....2....1....2
%e A246886 ..0....0....2....1....0....0....1....2....2....1....0....1....0....1....1....0
%e A246886 ..1....1....1....0....0....1....2....1....2....1....2....1....0....1....1....2
%K A246886 nonn
%O A246886 1,1
%A A246886 _R. H. Hardin_, Sep 06 2014