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 A074614 a(n) = 4^n + 9^n. 1

%I

%S 2,13,97,793,6817,60073,535537,4799353,43112257,387682633,3487832977,

%T 31385253913,282446313697,2541932937193,22877060890417,

%U 205892205836473,1853024483819137,16677198879535753,150094704016475857

%N a(n) = 4^n + 9^n.

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (13,-36).

%F a(n) = 2^(2*n) + 3^(2*n).

%F G.f.: (2-13*x)/((1-4*x)*(1-9*x)).

%F E.g.f.: e^(4*x) + e^(10*x). - _Mohammad K. Azarian_, Jan 11 2009

%F a(n) = 13*a(n-1) - 36*a(n-2) with a(0)=2, a(1)=13. - _Vincenzo Librandi_, Jul 21 2010

%t Table[4^n + 9^n, {n, 0, 25}]

%t LinearRecurrence[{13,-36},{2,13},30] (* _Harvey P. Dale_, Aug 11 2017 *)

%o (PARI) a(n)=4^n+9^n \\ _Charles R Greathouse IV_, Jul 01 2016

%Y Cf. A000051, A034472, A052539, A034474, A062394, A034491, A062395, A062396, A063376, A063481, A074600..A074624.

%Y Bisection of A007689 (even indexed members). For odd indexed members divided by 5 see A096951.

%K easy,nonn

%O 0,1

%A _Robert G. Wilson v_, Aug 26 2002

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Last modified March 26 23:16 EDT 2019. Contains 321566 sequences. (Running on oeis4.)