OFFSET
0,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..10000
Steven R. Finch, Tauberian Constants, August 30, 2004 [Cached copy, with permission of the author]
Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 68.
Eric Weisstein's MathWorld, Exponential Integral
FORMULA
C_1 also equals gamma + log(log(2)) + 2*Gamma(0, log(2)), where Gamma is the incomplete gamma function.
EXAMPLE
0.96804483044204448704848730112285492269036397005924632964...
MAPLE
evalf(gamma + log(log(2)) - 2*Ei(-log(2)), 120); # Vaclav Kotesovec, Oct 27 2014
MATHEMATICA
C1 = EulerGamma + Log[Log[2]] - 2*ExpIntegralEi[-Log[2]]; RealDigits[C1, 10, 103] // First
PROG
(PARI) Euler + log(log(2)) + 2*eint1(log(2)) \\ Altug Alkan, Sep 05 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Oct 27 2014
STATUS
approved