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A135002 Decimal expansion of 2/e. 4
7, 3, 5, 7, 5, 8, 8, 8, 2, 3, 4, 2, 8, 8, 4, 6, 4, 3, 1, 9, 1, 0, 4, 7, 5, 4, 0, 3, 2, 2, 9, 2, 1, 7, 3, 4, 8, 9, 1, 6, 2, 2, 2, 6, 2, 0, 6, 3, 5, 3, 5, 6, 6, 9, 0, 1, 5, 6, 7, 3, 6, 0, 3, 3, 9, 4, 9, 2, 2, 9, 9, 1, 4, 8, 9, 7, 9, 9, 6 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

From Johannes W. Meijer, Jun 27 2016: (Start)

This constant is related to the values of zeta(2*n-1) of the Riemann zeta function and the Euler Mascheroni constant gamma. If we define Z(n) = (1/n) * (sum(zeta(2*n-2*k-1) * Z(k), k=0..n-2) + gamma * Z(n-1)), with Z(0) = 1, then limit(Z(n), n -> infinity) = 2/exp(1).

Similar formulas appear in A163930 and A112302.

The structure of the n! * Z(n) formulas leads to the multinomial coefficients A036039. (End).

LINKS

Table of n, a(n) for n=0..78.

FORMULA

Integral of log x from x = 1/e to e. - Charles R Greathouse IV, Apr 16 2015

Equals lim_{k->0} 2*(1 - k)^(1/k). - Ilya Gutkovskiy, Jun 27 2016

EXAMPLE

0.735758882342... = 2*A068985.

MAPLE

evalf(2/exp(1)) ; # R. J. Mathar, Jul 14 2013

MATHEMATICA

RealDigits[2/E, 10, 120][[1]] (* Harvey P. Dale, Dec 25 2013 *)

PROG

(PARI) 2*exp(-1) \\ Charles R Greathouse IV, Apr 16 2015

CROSSREFS

Sequence in context: A213085 A119714 A154889 * A175452 A084714 A256779

Adjacent sequences:  A134999 A135000 A135001 * A135003 A135004 A135005

KEYWORD

cons,nonn

AUTHOR

Omar E. Pol, Nov 15 2007

STATUS

approved

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Last modified December 10 23:13 EST 2016. Contains 279021 sequences.