A053745 - OEIS

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A053745

Positions of '1's in the decimal expansion of Pi (where positions 1,2,3,... refer to the digits 3,1,4,...).

2, 4, 38, 41, 50, 69, 95, 96, 104, 111, 139, 149, 154, 155, 156, 164, 169, 175, 176, 199, 207, 221, 239, 244, 247, 251, 270, 282, 296, 298, 315, 320, 325, 343, 345, 363, 364, 382, 386, 391, 394, 396, 397, 418

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for sequences related to the number Pi

FORMULA

a(n) = 1 + A037000(n), a variant where position 1 is the first digit after the decimal point. - M. F. Hasler, Mar 20 2017

a(n) ~ 10*n if Pi is normal (as generally assumed but yet unproved). - M. F. Hasler, Jul 29 2024

MATHEMATICA

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

PROG

(PARI) A053745_upto(N=444, d=1)={localprec(N+20); [i|i<-[1..#N=digits(Pi\10^-N)], N[i]==d]} \\ M. F. Hasler, Jul 29 2024, replacing earlier code from 2017

CROSSREFS

Cf. A014976, A053746 - A053753 (the same for digits 0, ..., 9).

Cf. A088565 (primes in this sequence), A000796 (decimal digits of Pi).

Sequence in context: A018304 A289988 A051692 * A019275 A012433 A012438

Adjacent sequences: A053742 A053743 A053744 * A053746 A053747 A053748

KEYWORD

nonn,base

AUTHOR

Simon Plouffe, Feb 20 2000

STATUS

approved