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URL: https://oeis.org/A243955

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A243955
a(n) is the starting position of the first occurrence of a string of n 9's in the decimal expansion of 2*Pi.
1
12, 79, 761, 761, 761, 761, 761, 36356642, 1068822186
OFFSET
1,1
COMMENTS
This sequence denotes the position of the Feynman point in the digits of tau = 2*Pi, from a(3) to a(7). Note how compared with A048940, tau has a Feynman point one digit longer, and one position lower, because at this point, the decimal expansion of Pi is 499999987, giving 99999997 when multiplied by 2.
LINKS
Eric Weisstein's World of Mathematics, Feynman Point
EXAMPLE
The position of one consecutive 9 in 2*Pi=6.283185307179 is on the 12th decimal digit.
CROSSREFS
Cf. A048940 (similar, with Pi), A019692 (decimal expansion of 2*Pi).
Sequence in context: A035042 A061593 A344728 * A232044 A190216 A160559
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
a(9) from Chai Wah Wu, Sep 30 2019
STATUS
approved