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 A036254 #6 May 19 2013 12:18:40
%S A036254 1,1,5,6,35,321,677,4383,22592,72159,383387,3139255,28636682,
%T A036254 203596029,1861000943,5786598858,13434198659,46089194835,382147757339,
%U A036254 1574680224191,9830229102485,21235138429161,137241059677451,570199377138965,1847839191094346
%N A036254 Denominator of fraction equal to the continued fraction [ 3, 1, 4, 1, 5... ] (first n digits of Pi).
%H A036254 Harvey P. Dale, <a href="/A036254/b036254.txt">Table of n, a(n) for n = 1..1000</a>
%t A036254 nn=50;With[{pids=RealDigits[Pi,10,nn][[1]]},Denominator[Table[ FromContinuedFraction[ Take[pids,n]],{n,nn}]]] (* _Harvey P. Dale_, Feb 09 2013 *)
%Y A036254 Cf. A036253.
%K A036254 frac,nonn,base
%O A036254 1,3
%A A036254 _Jeff Burch_
%E A036254 More terms from _Harvey P. Dale_, Feb 09 2013