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%I #20 Jan 02 2019 12:56:17
%S 153,983,3503,3992,4508,6116,6803,6963,8366,11730,12527,12611,12700,
%T 12701,13597,14375,15190,16732,16733,19627,22270,22897,23208,23244,
%U 23660,25205,25448,25752,27053,29492,29687,29810,31281,31488,32498
%N Starting positions of strings of 3 1's in the decimal expansion of Pi.
%C The "position" is the number of digits to the right of the decimal point. - _Harvey P. Dale_, Jan 02 2019
%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>
%p Pidigs:= convert(evalf[40000](Pi),string):
%p StringTools[SearchAll]("111",Pidigs[3..-1]); # _Robert Israel_, Jan 09 2015
%t a=RealDigits[Pi,10,9! ];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];d=a[[1]][[n+2]];If[b==1&&c==1&&d==1,AppendTo[lst,n-1]],{n,9!-2}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 02 2009 *)
%t SequencePosition[RealDigits[Pi,10,33000][[1]],{1,1,1}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jan 02 2019 *)
%Y Cf. A000796.
%K nonn,base
%O 1,1
%A _Eric W. Weisstein_
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