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A083602 Starting positions of strings of four 1's in the decimal expansion of Pi.

%I A083602 #24 Feb 16 2025 08:32:49
%S A083602 12700,16732,32788,32789,37230,43154,48665,55716,87323,91195,92410,
%T A083602 93535,120459,120460,123036,123954,140159,141899,141900,145690,149927,
%U A083602 159573,172049,175018,191909,209140,215209,248918,255945,255946,255947
%N A083602 Starting positions of strings of four 1's in the decimal expansion of Pi.
%H A083602 Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>
%H A083602 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PiDigits.html">Pi Digits.</a>
%H A083602 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%t A083602 $MaxPrecision=10^8;a=RealDigits[Pi,10,3*9! ];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];d=a[[1]][[n+2]];e=a[[1]][[n+3]];If[b==1&&c==1&&d==1&&e==1,AppendTo[lst,n-1]],{n,7!,3*9!-3}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 07 2009 *)
%t A083602 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==1&&c==1&&d==1&&e==1,AppendTo[lst,n-1]],{n,9!-5}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 05 2009 *)
%t A083602 Flatten[Position[Partition[RealDigits[Pi,10,260000][[1]],4,1], _?(#=={1,1,1,1}&)]-1]  (* _Harvey P. Dale_, Apr 21 2011 *)
%t A083602 SequencePosition[RealDigits[Pi,10,256000][[1]],{1,1,1,1}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 26 2020 *)
%Y A083602 Cf. A050209 (three 1's), A083603 (five 1's).
%K A083602 base,nonn
%O A083602 1,1
%A A083602 _Rick L. Shepherd_, May 01 2003