OFFSET
1,2
LINKS
Stanislav Sykora, Table of n, a(n) for n = 1..2000
Eric Weisstein's World of Mathematics, Dawson's Integral
Wikipedia, Dawson function
EXAMPLE
1.5019752682686114988...
MATHEMATICA
RealDigits[x /. FindRoot[-2*Sqrt[Pi]*Erfi[x]*x^2 + 2*E^x^2*x + Sqrt[Pi]*Erfi[x], {x, 1}, WorkingPrecision -> 105]][[1]] (* Jean-François Alcover, Nov 08 2012 *)
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
x = solve(z=1.0, 2.0, real(D2Dawson(z))) \\ Stanislav Sykora, Sep 17 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Sep 26 2007
STATUS
approved