A347909 Decimal expansion of Integral_{x=0..1} exp(-x^2) dx.

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

Offset: 0

Author

Jianing Song, Sep 18 2021

Keywords

• nonn
• easy
• cons

Examples

			0.74682413281242702539946743613185300535449968...
		

Crossrefs

Cf. A019704 (sqrt(Pi)/2 = Integral_{x=0..+oo} exp(-x^2) dx), A002161 (sqrt(Pi) = Integral_{x=-oo..+oo} exp(-x^2) dx).

Cf. A347910 (inverse integrand), A007680.

Programs

Mathematica

RealDigits[(Sqrt[Pi]/2) Erf[1], 10, 91][[1]]

PARI

intnum(x=0, 1, exp(-x^2)) \\ Michel Marcus, Sep 18 2021

Formula

Equals (sqrt(Pi)/2) * erf(1) = (sqrt(Pi)/(2*i)) * erfi(i).

Equals Sum_{k>=0} (-1)^k / ((2*k + 1)*k!). - Ilya Gutkovskiy, Sep 18 2021