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A245262
Decimal expansion of Dawson's integral at the inflection point.
3
4, 2, 7, 6, 8, 6, 6, 1, 6, 0, 1, 7, 9, 2, 8, 7, 9, 7, 4, 0, 6, 7, 5, 5, 6, 4, 2, 1, 1, 2, 6, 9, 5, 1, 9, 1, 9, 3, 6, 2, 4, 5, 5, 3, 4, 5, 2, 7, 8, 1, 9, 5, 8, 8, 7, 6, 3, 6, 0, 6, 0, 9, 7, 1, 9, 0, 3, 5, 2, 0, 5, 5, 9, 0, 8, 8, 3, 4, 0, 0, 3, 6, 9, 6, 4, 3, 9, 6, 9, 8, 3, 4, 2, 8, 4, 5, 8, 8, 9, 3, 4, 9, 1, 6
OFFSET
0,1
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.9 Hyperbolic volume constants, p. 512.
LINKS
Eric Weisstein's MathWorld, Dawson's Integral
Wikipedia, Dawson function
FORMULA
Equals xinfl/(2*xinfl^2-1), xinfl = A133843. - Stanislav Sykora, Sep 17 2014
EXAMPLE
0.427686616017928797406755642112695191936245534527819588763606097190352...
MATHEMATICA
digits = 104; DawsonF[x_] := Sqrt[Pi]*Erfi[x]/(2*Exp[x^2]); xi = x /. FindRoot[DawsonF''[x], {x, 3/2}, WorkingPrecision -> digits + 10]; RealDigits[DawsonF[xi], 10, digits] // First
PROG
(PARI) Erfi(z) = -I*(1.0-erfc(I*z));
Dawson(z) = 0.5*sqrt(Pi)*exp(-z*z)*Erfi(z); \\ same as F(x)=D_+(x) D2Dawson(z) = -2.0*(z + (1.0-2.0*z*z)*Dawson(z)); \\ 2nd derivative
xinfl = solve(z=1.0, 2.0, real(D2Dawson(z)));
x = Dawson(xinfl) \\ Stanislav Sykora, Sep 17 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
STATUS
approved