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A232247
Decimal expansion of the arctan of 2/Pi.
5
5, 6, 6, 9, 1, 1, 5, 0, 4, 9, 4, 1, 0, 0, 9, 4, 0, 5, 0, 8, 2, 8, 9, 7, 7, 4, 6, 7, 2, 2, 6, 1, 9, 1, 5, 3, 8, 0, 6, 4, 8, 0, 2, 3, 9, 0, 9, 2, 6, 8, 2, 3, 3, 5, 7, 5, 7, 7, 5, 9, 4, 7, 2, 0, 4, 5, 8, 9, 3, 0, 1, 1, 7, 5, 9, 7, 0, 9, 1, 8, 2, 7, 5, 3, 1, 0
OFFSET
0,1
FORMULA
Equals A019669 - A232182.
Equals Sum_{k>=0} (-1)^k*(2/Pi)^(1+2*k)/(1+2*k).
EXAMPLE
0.56691150494100940508289774672261915380648023909268233575775947204589...
MAPLE
evalf(arctan(2/Pi));
MATHEMATICA
RealDigits[ArcTan[2/Pi], 10, 90][[1]]
PROG
(PARI) atan(2/Pi) \\ Charles R Greathouse IV, Mar 24 2021
CROSSREFS
Sequence in context: A205852 A028314 A201326 * A200110 A189240 A081820
KEYWORD
nonn,cons
AUTHOR
Bruno Berselli, Nov 21 2013
STATUS
approved