OFFSET
0,2
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.4 Golomb-Dickman Constant, p. 285.
LINKS
Eric Weisstein's MathWorld, Golomb-Dickman Constant
Wikipedia, Golomb-Dickman constant
FORMULA
v = integral_{0..infinity} x-e^Ei(-x)*x dx - (integral_{0..infinity} 1-e^Ei(-x) dx)^2, where Ei is the exponential integral function. [corrected by Vaclav Kotesovec, Aug 12 2019]
EXAMPLE
0.03690783006485220217710700292932764...
MAPLE
evalf(int((x-exp(Ei(-x))*x), x=0..infinity) - int( (1-exp(Ei(-x))), x=0..infinity)^2, 50); # Vaclav Kotesovec, Aug 12 2019
MATHEMATICA
v = NIntegrate[x - E^ExpIntegralEi[-x]*x, {x, 0, Infinity}, WorkingPrecision -> 80] - NIntegrate[1 - E^ExpIntegralEi[-x], {x, 0, Infinity}, WorkingPrecision -> 80]^2; Join[{0}, RealDigits[v, 10, 40] // First]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Sep 16 2014
EXTENSIONS
More digits from Vaclav Kotesovec, Aug 12 2019
STATUS
approved