A053753 Positions of 9's in the decimal expansion of Pi.

6, 13, 15, 31, 39, 43, 45, 46, 56, 59, 63, 80, 81, 101, 123, 130, 145, 170, 181, 188, 191, 194, 200, 209, 215, 248, 250, 260, 285, 295, 329, 332, 337, 342, 354, 357, 389, 392, 400, 415, 417, 419, 423, 434, 441, 460, 461, 466, 483, 488, 497, 499, 502, 528, 530, 534, 543, 550

Offset: 1

Author

Simon Plouffe, Feb 20 2000

Keywords

• nonn
• base

Comments

Here "position" is 1, 2, 3, ... for the digits 3, 1, 4, ..., in contrast to A037007(n) = a(n)-1 and other sequences (A048940, A096763, ...) using "offset 0" for the position. - M. F. Hasler, Mar 20 2017

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Index entries for sequences related to the number Pi
• R. K. Hoeflin, Ultra Test. [Fixed broken link, replaced deleted page by web.archive backup, but the reference seems irrelevant. - _M. F. Hasler_, Mar 20 2017]

Crossrefs

Cf. A037007, A048940, A096763, and the link to the OEIS index.

Programs

Mathematica

Flatten[Position[RealDigits[Pi, 10, 1000][[1]], 9]] (* Vincenzo Librandi, Oct 07 2013 *)

PARI

default(realprecision,1999);for(i=2,#T=Vec(Str(Pi)),T[i-1]=="9"&&print1(i-2",")) \\ Exclude last digit from search. - M. F. Hasler, Mar 20 2017