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 A050245 #19 Feb 16 2025 08:32:40
%S A050245 117,211,257,276,309,377,516,592,892,969,981,1216,1287,1331,1528,1550,
%T A050245 1772,1809,1894,2440,2441,2542,2747,2920,3051,3091,3127,3151,3152,
%U A050245 3210,3746,3875,3995,4000,4001,4026,4066,4129,4162,4192,4279,4296
%N A050245 Starting positions of strings of 2 6's in the decimal expansion of Pi.
%H A050245 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>
%H A050245 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A050245 q=8!;z=6;a=RealDigits[Pi,10,q];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];If[b==z&&c==z,AppendTo[lst,n-1]],{n,q-1}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 19 2009 *)
%t A050245 SequencePosition[RealDigits[Pi,10,5000][[1]],{6,6}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 11 2017 *)
%K A050245 nonn,base
%O A050245 1,1
%A A050245 _Eric W. Weisstein_