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

12700, 16732, 32788, 32789, 37230, 43154, 48665, 55716, 87323, 91195, 92410, 93535, 120459, 120460, 123036, 123954, 140159, 141899, 141900, 145690, 149927, 159573, 172049, 175018, 191909, 209140, 215209, 248918, 255945, 255946, 255947

Offset

1,1

Links

Table of n, a(n) for n=1..31.

Dave Andersen, Pi-Search Page

Eric Weisstein's World of Mathematics, Pi Digits.

Index entries for sequences related to the number Pi

Mathematica

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

Crossrefs

Cf. A050209 (three 1's), A083603 (five 1's).

Sequence in context: A254799 A254806 A253815 * A105655 A124411 A256809

Adjacent sequences: A083599 A083600 A083601 * A083603 A083604 A083605

Keyword

base,nonn

Author

Rick L. Shepherd, May 01 2003

Status

approved