A053753 - OEIS

%I #24 Mar 20 2017 12:54:11

%S 6,13,15,31,39,43,45,46,56,59,63,80,81,101,123,130,145,170,181,188,

%T 191,194,200,209,215,248,250,260,285,295,329,332,337,342,354,357,389,

%U 392,400,415,417,419,423,434,441,460,461,466,483,488,497,499,502,528,530,534,543,550

%N Positions of 9's in the decimal expansion of Pi.

%C 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

%H Vincenzo Librandi, <a href="/A053753/b053753.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>

%H R. K. Hoeflin, <a href="http://web.archive.org/web/20110728004205/http://www.eskimo.com/~miyaguch/ultra.html">Ultra Test</a>. [Fixed broken link, replaced deleted page by web.archive backup, but the reference seems irrelevant. - _M. F. Hasler_, Mar 20 2017]

%t Flatten[Position[RealDigits[Pi, 10, 1000][[1]], 9]] (* _Vincenzo Librandi_, Oct 07 2013 *)

%o (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

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

%K nonn,base

%O 1,1

%A _Simon Plouffe_, Feb 20 2000