A249385 Decimal expansion of gamma - 2*Ei(-1), one of the Tauberian constants, where Ei is the exponential integral function.

1, 0, 1, 5, 9, 8, 3, 5, 3, 3, 6, 9, 2, 5, 7, 3, 4, 0, 7, 9, 6, 0, 8, 3, 9, 6, 4, 1, 0, 0, 2, 6, 4, 5, 7, 2, 9, 1, 0, 4, 2, 5, 3, 9, 2, 2, 7, 5, 3, 7, 4, 0, 0, 1, 3, 9, 6, 1, 7, 2, 4, 4, 6, 1, 0, 3, 2, 0, 0, 5, 1, 2, 3, 8, 9, 5, 9, 4, 7, 7, 6, 0, 3, 8, 1, 3, 6, 7, 5, 6, 5, 3, 6, 2, 0, 2, 1, 2, 4, 9, 4, 2, 4

Offset

1,4

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Steven R. Finch, Tauberian Constants, August 30, 2004 [Cached copy, with permission of the author]

Eric Weisstein's MathWorld, Exponential Integral

Formula

Also equals gamma + 2*G/e, where G is the Euler-Gompertz constant 0.596347...

Equals A001620 + 2*A073003/e. - G. C. Greubel, Sep 04 2018

Example

1.01598353369257340796083964100264572910425392275374...

Maple

evalf(gamma - 2*Ei(-1), 120); # Vaclav Kotesovec, Oct 27 2014

Mathematica

RealDigits[ EulerGamma - 2*ExpIntegralEi[-1], 10, 103] // First

Prog

(PARI) default(realprecision, 100); Euler + 2*eint1(1) \\ G. C. Greubel, Sep 04 2018

Crossrefs

Cf. A001620, A073003, A099285, A248472.

Sequence in context: A366841 A153610 A357464 * A347216 A247747 A308577

Adjacent sequences: A249382 A249383 A249384 * A249386 A249387 A249388

Keyword

nonn,cons,easy

Author

Jean-François Alcover, Oct 27 2014

Status

approved