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Starting positions of strings of seven 4's in the decimal expansion of Pi.
3

%I #23 Mar 05 2020 22:41:26

%S 17893953,22931745,22931746,23189751,23724968,26621347,48484522,

%T 65122865,65122866,101281206,114016129,139676210,143452823,158136797,

%U 162805048,180943775,183739324,187015739,193053713,195259463,199439192

%N Starting positions of strings of seven 4's in the decimal expansion of Pi.

%C The digits 3,1,4,... of Pi are indexed by 0,1,2,...

%C Consecutive numbers indicate a string of more than seven '4's in a row, e.g., at positions 22931745, 65122865, 221749424, 351988052, ... start runs of eight '4's. - _M. F. Hasler_, Mar 21 2017

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

%H James Taylor, <a href="http://www.subidiom.com/pi/">Irrational Number Search Engine</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 SequencePosition[RealDigits[Pi,10,2*10^8][[1]],{4,4,4,4,4,4,4}][[All,1]]-1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 05 2020 *)

%Y Cf. A083618 (six 4's).

%K base,nonn

%O 1,1

%A _Rick L. Shepherd_, May 02 2003

%E More terms from _Rick L. Shepherd_, Aug 06 2006