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 A013727 #31 Jul 12 2025 08:38:57 %S A013727 22,10648,5153632,2494357888,1207269217792,584318301411328, %T A013727 282810057883082752,136880068015412051968,66249952919459433152512, %U A013727 32064977213018365645815808,15519448971100888972574851072,7511413302012830262726227918848,3635524038174209847159494312722432 %N A013727 a(n) = 22^(2*n + 1). %H A013727 Vincenzo Librandi, <a href="/A013727/b013727.txt">Table of n, a(n) for n = 0..200</a> %H A013727 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>. %H A013727 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (484). %F A013727 From _Philippe Deléham_, Nov 28 2008: (Start) %F A013727 a(n) = 484*a(n-1); a(0)=22. %F A013727 G.f.: 22/(1-484*x). (End) %F A013727 From _Elmo R. Oliveira_, Jul 10 2025: (Start) %F A013727 E.g.f.: 22*exp(484*x). %F A013727 a(n) = A004171(n)*A013716(n) = A009966(A005408(n)). (End) %p A013727 seq(22^(2*n+1),n=0..10); # _Nathaniel Johnston_, Jun 26 2011 %t A013727 NestList[484*# &, 22, 15] (* _Paolo Xausa_, Jul 12 2025 *) %o A013727 (Magma) [22^(2*n+1): n in [0..15]]; // _Vincenzo Librandi_, Jun 26 2011 %o A013727 (PARI) a(n)=22^(2*n+1) \\ _Charles R Greathouse IV_, Jul 11 2016 %Y A013727 Bisection of A009966 (22^n). %Y A013727 Cf. A004171, A005408, A013708-A013726, A013728-A013729. %K A013727 nonn,easy %O A013727 0,1 %A A013727 _N. J. A. Sloane_