A308577 Decimal expansion of Integral_{x=0..infinity} exp(-x)/(1 + erf(sqrt(x))).

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, 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, 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

Offset

0,1

Links

Table of n, a(n) for n=0..105.

Example

Equals 0.5985017924490618300179988376616175749146889655229...

Maple

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

Mathematica

RealDigits[NIntegrate[1/(E^z (1 + Erf[Sqrt[z]])), {z, 0, Infinity}, PrecisionGoal -> 20]][[1]]
(* Second program: *)
digits = 105; dz = 50;
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];
While[Print["z0 = ", z0]; f[z0] != f[z0 - dz], z0 = z0 + dz];
f[z0] (* Jean-François Alcover, Jun 18 2019 *)

Crossrefs

Sequence in context: A249385 A347216 A247747 * A217249 A091812 A112678

Adjacent sequences: A308574 A308575 A308576 * A308578 A308579 A308580

Keyword

nonn,cons

Author

Peter Luschny, Jun 08 2019

Extensions

More digits from Jean-François Alcover, Jun 18 2019

Status

approved