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%I #14 Jun 09 2016 11:59:47
%S 0,6,24,126,624,3126,15624,78126,390624,1953126,9765624,48828126,
%T 244140624,1220703126,6103515624,30517578126,152587890624,
%U 762939453126,3814697265624,19073486328126,95367431640624,476837158203126,2384185791015624,11920928955078126
%N a(n) = 5^n-(-1)^n.
%H Colin Barker, <a href="/A274072/b274072.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4,5).
%F O.g.f.: 6*x/((1+x)*(1-5*x)).
%F E.g.f.: exp(5*x) - exp(-x).
%F a(n) = 4*a(n-1) + 5*a(n-2) for n>1.
%F a(n) = 6*A015531(n).
%o (PARI) concat(0, Vec(6*x/((1+x)*(1-5*x)) + O(x^30)))
%Y Cf. A015531.
%Y Sequences of the type k^n-(-1)^n: A062157 (k=0), A010673 (k=1), A062510 (k=2), A105723 (k=3), A247281 (k=4), this sequence (k=5), A274073 (k=6).
%K nonn,easy
%O 0,2
%A _Colin Barker_, Jun 09 2016
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