A074602 - OEIS

%I #20 Jul 08 2024 21:42:50

%S 2,9,53,351,2417,16839,117713,823671,5765057,40354119,282476273,

%T 1977328791,13841291297,96889018599,678223089233,4747561542711,

%U 33232930635137,232630514118279,1628413598172593,11398895185897431

%N a(n) = 2^n + 7^n.

%H Vincenzo Librandi, <a href="/A074602/b074602.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 (9,-14).

%F a(n) = 7*a(n-1) - 2^n = 9*a(n-1) - 14*a(n-2).

%F From _Mohammad K. Azarian_, Jan 02 2009: (Start)

%F G.f.: 1/(1-2*x) + 1/(1-7*x).

%F E.g.f.: e^(2*x) + e^(7*x). (End)

%F a(n) = 2*A016130(n)-9*A016130(n-1). - _R. J. Mathar_, Mar 10 2022

%t Table[2^n + 7^n, {n, 0, 25}]

%o (Magma) [2^n + 7^n: n in [0..35]]; // _Vincenzo Librandi_, Apr 30 2011

%Y Cf. A000051, A034472, A052539, A034474, A062394, A034491, A062395, A062396, A007689, A063376, A063481, A074600 - A074624.

%K easy,nonn

%O 0,1

%A _Robert G. Wilson v_, Aug 25 2002