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A248472
Decimal expansion of C_1 = gamma + log(log(2)) - 2*Ei(-log(2)), one of the Tauberian constants, where Ei is the exponential integral function.
2
9, 6, 8, 0, 4, 4, 8, 3, 0, 4, 4, 2, 0, 4, 4, 4, 8, 7, 0, 4, 8, 4, 8, 7, 3, 0, 1, 1, 2, 2, 8, 5, 4, 9, 2, 2, 6, 9, 0, 3, 6, 3, 9, 7, 0, 0, 5, 9, 2, 4, 6, 3, 2, 9, 6, 4, 0, 9, 3, 1, 4, 0, 4, 6, 8, 3, 4, 1, 5, 6, 2, 4, 9, 1, 1, 6, 6, 1, 3, 1, 4, 3, 5, 9, 1, 5, 1, 2, 0, 1, 8, 1, 6, 6, 4, 2, 9, 5, 8, 9, 2, 4, 2
OFFSET
0,1
LINKS
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
STATUS
approved