A308577 - OEIS

%I #14 Jun 19 2019 02:25:58

%S 5,9,8,5,0,1,7,9,2,4,4,9,0,6,1,8,3,0,0,1,7,9,9,8,8,3,7,6,6,1,6,1,7,5,

%T 7,4,9,1,4,6,8,8,9,6,5,5,2,2,9,0,5,4,0,2,8,1,1,2,2,8,8,7,5,1,7,7,5,1,

%U 9,2,1,3,0,6,1,0,9,5,7,9,0,9,6,1,2,1,8,6,4,4,6,9,7,5,0,5,4,0,8,6,8,0,2,3,9,3

%N Decimal expansion of Integral_{x=0..infinity} exp(-x)/(1 + erf(sqrt(x))).

%e Equals 0.5985017924490618300179988376616175749146889655229...

%p evalf(Int(exp(-x)/(1 + erf(sqrt(x))), x=0..infinity, method=_Gquad), 110);

%t RealDigits[NIntegrate[1/(E^z (1 + Erf[Sqrt[z]])), {z, 0, Infinity}, PrecisionGoal -> 20]][[1]]

%t (* Second program: *)

%t digits = 105; dz = 50;

%t f[z0_] := f[z0] = NIntegrate[1/(E^z (1 + Erf[Sqrt[z]])), {z, 0, z0}, WorkingPrecision -> digits+5] + 1/(2 E^z0) // RealDigits[#, 10, digits][[1]]&; f[z0 = dz]; f[z0 = z0 + dz];

%t While[Print["z0 = ", z0]; f[z0] != f[z0 - dz], z0 = z0 + dz];

%t f[z0] (* _Jean-François Alcover_, Jun 18 2019 *)

%K nonn,cons

%O 0,1

%A _Peter Luschny_, Jun 08 2019

%E More digits from _Jean-François Alcover_, Jun 18 2019