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 A013718 #22 Sep 08 2022 08:44:38 %S A013718 13,2197,371293,62748517,10604499373,1792160394037,302875106592253, %T A013718 51185893014090757,8650415919381337933,1461920290375446110677, %U A013718 247064529073450392704413,41753905413413116367045797 %N A013718 a(n) = 13^(2*n + 1). %H A013718 Vincenzo Librandi, <a href="/A013718/b013718.txt">Table of n, a(n) for n = 0..200</a> %H A013718 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A013718 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (169). %F A013718 From _Philippe Deléham_, Nov 25 2008: (Start) %F A013718 a(n) = 169*a(n-1); a(0)=13. %F A013718 G.f.: 13/(1-169*x). (End) %p A013718 seq(13^(2*n+1),n=0..11); # _Nathaniel Johnston_, Jun 25 2011 %o A013718 (Magma) [13^(2*n+1): n in [0..15]]; // _Vincenzo Librandi_, Jun 26 2011 %o A013718 (PARI) a(n)=13^(2*n+1) \\ _Charles R Greathouse IV_, Jul 11 2016 %Y A013718 Bisection of A001022 (12^n). %Y A013718 Cf. A013708-A013717, A013719-A013729. %K A013718 nonn,easy %O A013718 0,1 %A A013718 _N. J. A. Sloane_