This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A017377 #50 May 27 2025 01:09:58 %S A017377 9,19,29,39,49,59,69,79,89,99,109,119,129,139,149,159,169,179,189,199, %T A017377 209,219,229,239,249,259,269,279,289,299,309,319,329,339,349,359,369, %U A017377 379,389,399,409,419,429,439,449,459,469,479,489,499,509,519,529,539 %N A017377 a(n) = 10*n + 9. %C A017377 Numbers k such that k^k ends with 9. - _Bruno Berselli_, Dec 11 2018 %D A017377 Alfred S. Posamentier, Math Charmers, Tantalizing Tidbits for the Mind, Prometheus Books, NY, 2003, pp. 126-127. %H A017377 Vincenzo Librandi, <a href="/A017377/b017377.txt">Table of n, a(n) for n = 0..5000</a> %H A017377 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>. %H A017377 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=979">Encyclopedia of Combinatorial Structures 979</a>. %H A017377 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1). %F A017377 a(n) = 10*n + 9; a(n) = 2*a(n-1) - a(n-2). - _Vincenzo Librandi_, May 29 2011 %F A017377 G.f.: (9+x)/(x-1)^2. - _R. J. Mathar_, Oct 16 2015 %F A017377 From _Elmo R. Oliveira_, Apr 05 2025: (Start) %F A017377 E.g.f.: exp(x)*(9 + 10*x). %F A017377 a(n) = A016897(2*n+1). (End) %t A017377 Range[9, 1000, 10] (* _Vladimir Joseph Stephan Orlovsky_, May 28 2011 *) %o A017377 (Magma) [10*n+9: n in [0..60]]; // _Vincenzo Librandi_, May 29 2011 %o A017377 (PARI) a(n)=10*n+9 \\ _Charles R Greathouse IV_, Feb 12 2017 %o A017377 (Sage) %o A017377 def A017377(n): return 10*n+9 %o A017377 print([A017377(n) for n in range(0,54)]) # _Stefano Spezia_, May 26 2025 %Y A017377 Cf. A008592, A016897, A017365, A190876. %K A017377 nonn,easy %O A017377 0,1 %A A017377 _N. J. A. Sloane_