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%I #40 Sep 08 2022 08:44:42
%S 9,19,29,39,49,59,69,79,89,99,109,119,129,139,149,159,169,179,189,199,
%T 209,219,229,239,249,259,269,279,289,299,309,319,329,339,349,359,369,
%U 379,389,399,409,419,429,439,449,459,469,479,489,499,509,519,529,539
%N a(n) = 10*n + 9.
%C Numbers k such that k^k ends with 9. - _Bruno Berselli_, Dec 11 2018
%H Vincenzo Librandi, <a href="/A017377/b017377.txt">Table of n, a(n) for n = 0..5000</a>
%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>
%H INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=979">Encyclopedia of Combinatorial Structures 979</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F a(n) = 10*n + 9; a(n) = 2*a(n-1) - a(n-2). - _Vincenzo Librandi_, May 29 2011
%F G.f.: ( 9+x ) / (x-1)^2 . - _R. J. Mathar_, Oct 16 2015
%t Range[9, 1000, 10] (* _Vladimir Joseph Stephan Orlovsky_, May 28 2011 *)
%o (Magma) [10*n+9: n in [0..60]]; // _Vincenzo Librandi_, May 29 2011
%o (PARI) a(n)=10*n+9 \\ _Charles R Greathouse IV_, Feb 12 2017
%Y Cf. A008592, A017365, A190876.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_
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