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 A050272 #17 Feb 16 2025 08:32:40
%S A050272 44,79,459,705,747,762,763,764,765,766,777,1063,1073,1385,1395,1428,
%T A050272 1477,1532,1730,1981,2000,2071,2114,2218,2241,2285,2335,2436,2644,
%U A050272 2796,2910,2949,2950,3089,3217,3294,3508,3564,3570,3673,3678,3710
%N A050272 Starting positions of strings of 2 9's in the decimal expansion of Pi.
%H A050272 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%H A050272 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>
%t A050272 q=8!;z=9;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 A050272 Transpose[SequencePosition[RealDigits[Pi,10,4000][[1]],{9,9}]][[1]]-1 (* The program uses the SequencePosition function from Mathematica version 10 *) (* _Harvey P. Dale_, Dec 27 2015 *)
%K A050272 nonn,base
%O A050272 1,1
%A A050272 _Eric W. Weisstein_