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a(n) = 2^n + 6^n + 7^n.
1

%I #16 Sep 08 2022 08:45:07

%S 3,15,89,567,3713,24615,164369,1103607,7444673,50431815,342942449,

%T 2340125847,16018073633,109949712615,756587253329,5217746527287,

%U 36054040542593,249557173563015,1729973554841009,12008254925907927

%N a(n) = 2^n + 6^n + 7^n.

%H Vincenzo Librandi, <a href="/A074541/b074541.txt">Table of n, a(n) for n = 0..200</a>

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (15,-68,84).

%F From _Mohammad K. Azarian_, Dec 27 2008: (Start)

%F G.f.: 1/(1-2*x) + 1/(1-6*x) + 1/(1-7*x).

%F E.g.f.: exp(2*x) + exp(6*x) + exp(7*x). (End)

%t Table[2^n + 6^n + 7^n, {n, 0, 20}]

%o (Magma) [2^n + 6^n + 7^n: n in [0..25]]; // _Vincenzo Librandi_, Jun 11 2011

%Y Cf. A001550, A001576, A034513, A001579, A074501 - A074580.

%K easy,nonn

%O 0,1

%A _Robert G. Wilson v_, Aug 23 2002