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 A083604 #17 Feb 16 2025 08:32:49
%S A083604 255945,2645268,3218870,4657555,4657556,5130874,5425806,5961931,
%T A083604 6653783,9036112,11867965,13249047,13255651,15684440,18548887,
%U A083604 20316848,22107705,22564362,23503699,28388441,28580580,29435972,30584158,31678241
%N A083604 Starting positions of strings of six 1's in the decimal expansion of Pi.
%H A083604 Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>
%H A083604 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits.</a>
%H A083604 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A083604 $MaxPrecision=10^8;a=RealDigits[Pi,10,8*9! ];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];d=a[[1]][[n+2]];e=a[[1]][[n+3]];f=a[[1]][[n+4]];g=a[[1]][[n+5]];If[b==1&&c==1&&d==1&&e==1&&f==1&&g==1,AppendTo[lst,n-1]],{n,2*8!,8*9!-5}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 07 2009 *)
%t A083604 SequencePosition[RealDigits[Pi,10,32*10^6][[1]],{1,1,1,1,1,1}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 04 2018 *)
%Y A083604 Cf. A083603 (five 1's), A083605 (seven 1's).
%K A083604 base,nonn
%O A083604 1,1
%A A083604 _Rick L. Shepherd_, May 01 2003