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 A083610 #17 Feb 16 2025 08:32:49
%S A083610 1698,4928,6917,7651,8413,8736,8828,12520,17614,21973,22580,22704,
%T A083610 22749,23471,25094,25179,28467,28468,28469,30583,32631,33095,35838,
%U A083610 37507,38597,41392,42438,42734,45756,48033,48207,48369,49287,50547,52794
%N A083610 Starting positions of strings of three 3's in the decimal expansion of Pi.
%H A083610 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%H A083610 Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>
%H A083610 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits</a>
%t A083610 q=9!;z=3;a=RealDigits[Pi,10,q];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];d=a[[1]][[n+2]];If[b==z&&c==z&&d==z,AppendTo[lst,n-1]],{n,q-2}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 19 2009 *)
%t A083610 Flatten[Position[Partition[RealDigits[Pi,10,53000][[1]],3,1],{3,3,3}]]-1 (* _Harvey P. Dale_, Mar 05 2015 *)
%Y A083610 Cf. A050222 (two 3's), A083611 (four 3's).
%K A083610 base,nonn
%O A083610 1,1
%A A083610 _Rick L. Shepherd_, May 01 2003