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A242978
Decimal expansion of Efimov's scaling constant.
0
2, 2, 6, 9, 4, 3, 8, 2, 5, 9, 5, 3, 6, 6, 6, 9, 5, 1, 9, 2, 8, 6, 0, 2, 1, 7, 1, 3, 6, 9, 3, 3, 3, 7, 6, 5, 1, 0, 2, 9, 8, 9, 6, 8, 9, 0, 1, 3, 0, 3, 1, 9, 1, 3, 6, 4, 8, 2, 6, 0, 8, 9, 4, 1, 6, 4, 2, 7, 1, 7, 1, 2, 9, 5, 6, 9, 8, 3, 0, 4, 2, 9, 0, 4, 9, 2, 5
OFFSET
2,1
COMMENTS
Usually reported as 22.7.
LINKS
V. N. Efimov, Weakly-bound states of three resonantly-interacting particles, Soviet Journal of Nuclear Physics 12:5 (1971), pp. 589-595. [Yad. Fiz. 12 (1970), 1080].
Wikipedia, Efimov state
MATHEMATICA
RealDigits[E^(Pi/x)/.FindRoot[x*Cosh[Pi*x/2] - 8*Sinh[Pi*x/6]/Sqrt[3], {x, 2}, WorkingPrecision->105]][[1]] (* Vaclav Kotesovec, May 28 2014 *)
PROG
(PARI) exp(Pi/solve(x=1, 2, x*cosh(Pi*x/2)-8*sinh(Pi*x/6)/sqrt(3)))
CROSSREFS
Sequence in context: A169800 A094485 A331988 * A345308 A231137 A371400
KEYWORD
nonn,cons
AUTHOR
STATUS
approved