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.

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

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

Cf. A001620, A074785, A249385.

Sequence in context: A011012 A157989 A243265 * A306553 A011194 A235916

Adjacent sequences: A248469 A248470 A248471 * A248473 A248474 A248475

Keyword

nonn,cons

Author

Jean-François Alcover, Oct 27 2014

Status

approved