A083607 Starting positions of strings of four 2's in the decimal expansion of Pi.

4902, 7964, 12486, 43405, 50271, 55736, 62920, 65260, 65261, 71778, 83521, 97191, 98423, 103025, 105290, 123462, 125053, 125172, 125656, 138493, 138655, 150949, 162191, 192255, 196397, 204561, 204850, 209562, 216368, 216660, 267139, 272809

Offset

1,1

Links

Table of n, a(n) for n=1..32.

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, 9! ]; lst={}; Do[b=a[[1]][[n]]; c=a[[1]][[n+1]]; d=a[[1]][[n+2]]; e=a[[1]][[n+3]]; If[b==2&&c==2&&d==2&&e==2, AppendTo[lst, n-1]], {n, 6*6!, 9!-3}]; lst (* Vladimir Joseph Stephan Orlovsky, Jun 07 2009 *)
With[{p=Partition[Rest[RealDigits[Pi, 10, 300000][[1]]], 4, 1]}, Flatten[ Position[ p, {2, 2, 2, 2}]]] (* Harvey P. Dale, Oct 10 2011 *)
Module[{nn=300000, pid}, pid=RealDigits[Pi, 10, nn][[1]]; SequencePosition[ pid, {2, 2, 2, 2}]][[All, 1]]-1 (* Harvey P. Dale, Jan 13 2023 *)

Crossrefs

Cf. A083606 (three 2's), A083608 (five 2's).

Sequence in context: A107545 A256363 A031568 * A168028 A031834 A031634

Adjacent sequences: A083604 A083605 A083606 * A083608 A083609 A083610

Keyword

base,nonn

Author

Rick L. Shepherd, May 01 2003

Status

approved