login
Starting positions of strings of three 5's in the decimal expansion of Pi.
1

%I #16 Aug 23 2021 18:10:31

%S 177,1232,1450,2359,2674,7245,7317,7681,10145,10493,11319,14176,17052,

%T 18353,18717,18760,19811,20535,20982,21290,22011,22584,23103,24466,

%U 24467,24468,24820,24864,26364,26603,30014,31435,32029,32523,33172

%N Starting positions of strings of three 5's in the decimal expansion of Pi.

%C Each starting position is counted from the decimal point - _Harvey P. Dale_, Aug 23 2021

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

%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>

%t q=9!;z=5;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 SequencePosition[RealDigits[Pi,10,35000][[1]],{5,5,5}][[All,1]]-1 (* _Harvey P. Dale_, Aug 23 2021 *)

%Y Cf. A050238 (two 5's), A083621 (four 5's).

%K base,nonn

%O 1,1

%A _Rick L. Shepherd_, May 02 2003