OFFSET
0,2
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.4.2 Random mapping statistics, p. 290.
LINKS
Xavier Gourdon, Combinatoire, Algorithmique et Géométrie des Polynomes Ecole Polytechnique, Paris 1996, page 152 (in French)
Eric Weisstein's MathWorld, Flajolet-Odlyzko Constant
FORMULA
2*integral_{0..infinity} 1 - e^(Ei(-x)/2)*(1 - Ei(-x)/2) dx, where Ei is the exponential integral.
EXAMPLE
0.17090961985966239214460728413311738704719072962628832355853881...
MATHEMATICA
digits = 95; Ei = ExpIntegralEi; 2*NIntegrate[1 - E^(Ei[-x]/2)*(1 - Ei[-x]/2), {x, 0, 200}, WorkingPrecision -> digits + 5] // RealDigits[#, 10, digits]& // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Apr 29 2016
STATUS
approved