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

%I #23 Sep 26 2020 16:25:17

%S 12700,16732,32788,32789,37230,43154,48665,55716,87323,91195,92410,

%T 93535,120459,120460,123036,123954,140159,141899,141900,145690,149927,

%U 159573,172049,175018,191909,209140,215209,248918,255945,255946,255947

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

%H Dave Andersen, <a href="http://www.angio.net/pi/piquery">Pi-Search Page</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PiDigits.html">Pi Digits.</a>

%H <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>

%t $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 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 Flatten[Position[Partition[RealDigits[Pi,10,260000][[1]],4,1], _?(#=={1,1,1,1}&)]-1] (* _Harvey P. Dale_, Apr 21 2011 *)

%t 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 Cf. A050209 (three 1's), A083603 (five 1's).

%K base,nonn

%O 1,1

%A _Rick L. Shepherd_, May 01 2003

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Last modified March 28 11:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)