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 A050254 #17 Feb 16 2025 08:32:40
%S A050254 559,621,625,633,739,742,890,948,954,1066,1087,1179,1261,1307,1545,
%T A050254 1589,1590,1591,1630,1704,1953,2049,2173,2212,2325,2337,2471,2672,
%U A050254 3057,3074,3111,3278,3282,3806,3941,4143,4208,4345,4441,4575,4576
%N A050254 Starting positions of strings of 2 7's in the decimal expansion of Pi.
%H A050254 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>
%H A050254 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A050254 q=8!;z=7;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 *)
%K A050254 nonn,base
%O A050254 1,1
%A A050254 _Eric W. Weisstein_