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 A083607 #20 Feb 16 2025 08:32:49
%S A083607 4902,7964,12486,43405,50271,55736,62920,65260,65261,71778,83521,
%T A083607 97191,98423,103025,105290,123462,125053,125172,125656,138493,138655,
%U A083607 150949,162191,192255,196397,204561,204850,209562,216368,216660,267139,272809
%N A083607 Starting positions of strings of four 2's in the decimal expansion of Pi.
%H A083607 Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>
%H A083607 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits.</a>
%H A083607 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A083607 $MaxPrecision=10^8;a=RealDigits[Pi,10,9! ];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];d=a[[1]][[n+2]];e=a[[1]][[n+3]];If[b==2&&c==2&&d==2&&e==2,AppendTo[lst,n-1]],{n,6*6!,9!-3}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 07 2009 *)
%t A083607 With[{p=Partition[Rest[RealDigits[Pi,10,300000][[1]]],4,1]}, Flatten[ Position[ p,{2,2,2,2}]]] (* _Harvey P. Dale_, Oct 10 2011 *)
%t A083607 Module[{nn=300000,pid},pid=RealDigits[Pi,10,nn][[1]];SequencePosition[ pid,{2,2,2,2}]][[All,1]]-1 (* _Harvey P. Dale_, Jan 13 2023 *)
%Y A083607 Cf. A083606 (three 2's), A083608 (five 2's).
%K A083607 base,nonn
%O A083607 1,1
%A A083607 _Rick L. Shepherd_, May 01 2003