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 A083611 #18 Feb 16 2025 08:32:49
%S A083611 28467,28468,66846,79979,84542,89085,89086,93498,95730,119658,145459,
%T A083611 146043,146044,150803,158335,162369,169124,172951,178501,186291,
%U A083611 190241,191664,193042,214252,217711,222180,231023,235521,263318,263955,297544
%N A083611 Starting positions of strings of four 3's in the decimal expansion of Pi.
%H A083611 Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>
%H A083611 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits.</a>
%H A083611 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A083611 Transpose[StringPosition[StringDrop[ToString[N[Pi,9! ]],2],"3333"]][[1]] (* _Vladimir Joseph Stephan Orlovsky_, Jun 19 2009 *)
%t A083611 Flatten[Position[Partition[RealDigits[Pi,10,300000][[1]],4,1],_?(#== {3,3,3,3}&)]]-1 (* _Harvey P. Dale_, Oct 25 2011 *)
%Y A083611 Cf. A083610 (three 3's), A083612 (five 3's).
%K A083611 base,nonn
%O A083611 1,1
%A A083611 _Rick L. Shepherd_, May 01 2003