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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 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Usually reported as 22.7.

LINKS

Table of n, a(n) for n=2..88.

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: A277510 A169800 A094485 * A231137 A188808 A021819

Adjacent sequences:  A242975 A242976 A242977 * A242979 A242980 A242981

KEYWORD

nonn,cons

AUTHOR

Charles R Greathouse IV, May 28 2014

STATUS

approved

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Last modified April 27 15:06 EDT 2017. Contains 285528 sequences.