OFFSET
0,1
LINKS
Eric Weisstein's World of Mathematics, Erf
FORMULA
Equals 1-A099287.
Equals (1/e) Sum_{n >= 0} (1/(n/2)!) - 1. - Jean-François Alcover, Jun 14 2020
From Amiram Eldar, Jul 22 2020: (Start)
Equals (2/sqrt(Pi)) * Integral_{x=0..1} exp(-x^2) dx.
Equals (2/sqrt(Pi)) * Sum_{k>=0} (-1)^k/(k! * (2*k + 1)) = (2/sqrt(Pi)) * Sum_{k>=0} (-1)^k/A007680(k).
Equals (1/e) * Sum_{k>=1} 1/Gamma(k + 1/2). (End)
EXAMPLE
0.84270079294971486934122063508260925929606699796630290845993789783...
MATHEMATICA
RealDigits[ Erf[1], 10, 105][[1]]
PROG
(PARI) 1 - erfc(1)
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Robert G. Wilson v, Oct 08 2004
STATUS
approved