%I #18 Jun 11 2017 14:06:27
%S 117,211,257,276,309,377,516,592,892,969,981,1216,1287,1331,1528,1550,
%T 1772,1809,1894,2440,2441,2542,2747,2920,3051,3091,3127,3151,3152,
%U 3210,3746,3875,3995,4000,4001,4026,4066,4129,4162,4192,4279,4296
%N Starting positions of strings of 2 6's in the decimal expansion of Pi.
%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 q=8!;z=6;a=RealDigits[Pi,10,q];lst={};Do[b=a[[1]][[n]];c=a[[1]][[n+1]];If[b==z&&c==z,AppendTo[lst,n-1]],{n,q-1}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 19 2009 *)
%t SequencePosition[RealDigits[Pi,10,5000][[1]],{6,6}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 11 2017 *)
%K nonn,base
%O 1,1
%A _Eric W. Weisstein_