OFFSET
1,2
COMMENTS
The unique real solution to the equation 2*arctan(x) - log(1 + x^2)/x = Pi/3.
EXAMPLE
1.263122213969262542026249040522580451860297573323877...
MATHEMATICA
RealDigits[r /. FindRoot[2*ArcTan[r] - Log[1 + r^2]/r == Pi/3, {r, 1}, WorkingPrecision -> 120]][[1]]
PROG
(PARI) solve(r = 1, 2, 2*atan(r) - log(1 + r^2)/r - Pi/3)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Amiram Eldar, Apr 30 2026
STATUS
approved
