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A277669 Number of n-length words over a 6-ary alphabet {a_1,a_2,...,a_6} avoiding consecutive letters a_i, a_{i+1}.

%I A277669 #8 Oct 26 2016 11:36:19
%S A277669 1,6,31,160,826,4264,22012,113632,586599,3028182,15632291,80698096,
%T A277669 416585304,2150525528,11101591924,57309407232,295846593873,
%U A277669 1527239790702,7884023093755,40699450421136,210101523661770,1084600646648368,5599000626972168,28903549078371648
%N A277669 Number of n-length words over a 6-ary alphabet {a_1,a_2,...,a_6} avoiding consecutive letters a_i, a_{i+1}.
%H A277669 Alois P. Heinz, <a href="/A277669/b277669.txt">Table of n, a(n) for n = 0..1000</a>
%H A277669 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-5,4,-3,2,-1)
%F A277669 G.f.: 1/(1 + Sum_{j=1..6} (7-j)*(-x)^j).
%p A277669 a:= n-> (<<0|1|0|0|0|0>, <0|0|1|0|0|0>, <0|0|0|1|0|0>,
%p A277669           <0|0|0|0|1|0>, <0|0|0|0|0|1>, <-1|2|-3|4|-5|6>>^n)[6$2]:
%p A277669 seq(a(n), n=0..30);
%Y A277669 Column k=6 of A277666.
%K A277669 nonn,easy
%O A277669 0,2
%A A277669 _Alois P. Heinz_, Oct 26 2016