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 A138199 #20 Sep 08 2022 08:45:33
%S A138199 17,2771,538067,105415691,20661066467,4049565346811,793714774848467,
%T A138199 155568095572161131,30491346729460336067,5976303958950076658651,
%U A138199 1171355575953997682201267,229585692886981589625399371,44998795805848373961803836067,8819763977946281138070581903291
%N A138199 a(n) = 14^(2*n+1) + 3^(2*n+1).
%C A138199 Subsequence of A008599; A138200(n) = a(n)/17.
%D A138199 F. Ischebeck, Einladung zur Zahlentheorie (BI Wissenschaftsverlag 1992), Aufgabe 7, p. 18.
%H A138199 Vincenzo Librandi, <a href="/A138199/b138199.txt">Table of n, a(n) for n = 0..100</a>
%H A138199 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (205, -1764).
%F A138199 a(0)=17, a(1)=2771; a(n) = 205*a(n-1)-1764*a(n-2). - _Harvey P. Dale_, Aug 13 2013
%F A138199 G.f.: 14/(1-196*x)+3/(1-9*x). -_Harvey P. Dale_, Aug 13 2013
%t A138199 Table[c=2n+1;14^c+3^c,{n,0,20}] (* or *) LinearRecurrence[{205,-1764},{17,2771},30] (* _Harvey P. Dale_, Aug 13 2013 *)
%t A138199 CoefficientList[Series[14/(1 - 196 x) + 3/(1 - 9 x), {x, 0, 25}], x] (* _Vincenzo Librandi_, May 23 2014 *)
%o A138199 (Magma)[14^(2*n+1)+3^(2*n+1): n in [0..20]]; // _Vincenzo Librandi_, Dec 27 2010
%Y A138199 Cf. A008599, A076311, A138200.
%K A138199 nonn,easy
%O A138199 0,1
%A A138199 _Reinhard Zumkeller_, Mar 05 2008
%E A138199 Corrected and extended by _Harvey P. Dale_, Aug 13 2013