A083642 Starting positions of strings of three 9's in the decimal expansion of Pi.

762, 763, 764, 765, 2949, 7759, 8527, 9962, 11197, 11382, 13019, 16687, 17119, 17561, 17988, 17989, 18680, 19437, 19438, 19446, 19447, 19448, 19748, 21579, 22309, 22753, 22754, 23989, 24107, 25584, 26069, 26490, 27602, 28122, 28320

Offset: 1

Author

Rick L. Shepherd, May 05 2003

Keywords

• base
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000
• Index entries for sequences related to the number Pi
• Dave Andersen, Pi-Search Page
• Eric Weisstein's World of Mathematics, Pi Digits.

Crossrefs

Cf. A050272 (two 9's), A083643 (four 9's).

Programs

Mathematica

Transpose[ StringPosition[ StringDrop[ ToString[ N[Pi, 28588]], 2], "999"]][[1]]
Flatten[With[{p=Partition[RealDigits[Pi,10,30000][[1]],3,1]},Position[p,{9,9,9}]]]-1 (* Harvey P. Dale, Jan 05 2013 *)
With[{pid=RealDigits[Pi,10,30000][[1]]},SequencePosition[pid,{9,9,9}]][[;;,1]]-1 (* Harvey P. Dale, Feb 18 2025 *)