%I #21 Sep 08 2022 08:45:07
%S 3,21,155,1197,9587,78981,664715,5684637,49202147,429727221,
%T 3779025275,33407214477,296514964307,2639975541861,23561119043435,
%U 210669211182717,1886405707312067,16910575153106901,151726863592175195
%N a(n) = 5^n + 7^n + 9^n.
%H Vincenzo Librandi, <a href="/A074575/b074575.txt">Table of n, a(n) for n = 0..300</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21,-143,315).
%F From _Mohammad K. Azarian_, Dec 26 2008: (Start)
%F G.f.: 1/(1-5*x) + 1/(1-7*x) + 1/(1-9*x).
%F E.g.f.: e^(5*x) + e^(7*x) + e^(9*x). (End)
%t Table[5^n + 7^n + 9^n, {n, 0, 20}]
%t LinearRecurrence[{21,-143,315},{3,21,155},20] (* _Harvey P. Dale_, Jul 14 2019 *)
%o (Magma) [5^n + 7^n + 9^n: n in [0..20]]; // _Vincenzo Librandi_, May 20 2011
%Y Cf. A001550, A001576, A034513, A001579, A074501-A074580.
%K easy,nonn
%O 0,1
%A _Robert G. Wilson v_, Aug 23 2002
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