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A053748
Positions of 4's in the decimal expansion of Pi.
3
3, 20, 24, 37, 58, 60, 61, 71, 88, 93, 105, 120, 126, 127, 146, 152, 158, 163, 183, 184, 189, 193, 202, 203, 218, 219, 224, 228, 252, 255, 263, 267, 272, 274, 279, 294, 297, 304, 322, 340, 349, 372, 377, 385, 387
OFFSET
1,1
FORMULA
a(n) = A037003(n) + 1. - Georg Fischer, May 31 2021
EXAMPLE
Pi starts off 3.141592653589793238462643383279502884197..., with 4s in the hundredths' (10^(-2)s') place, which is the third digit counting the 3 in the ones' place. Then there's another 4 at the 10^(-19)s' place, which is the twentieth digit counting the initial 3. [Alonso del Arte, Oct 07 2013]
MATHEMATICA
Flatten[Position[RealDigits[Pi, 10, 1000][[1]], 4]] (* Vincenzo Librandi, Oct 07 2013 *)
CROSSREFS
Sequence in context: A222482 A022129 A308721 * A075358 A352810 A002461
KEYWORD
nonn,base
AUTHOR
Simon Plouffe, Feb 20 2000
STATUS
approved