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A019739 Decimal expansion of E/2. 3
1, 3, 5, 9, 1, 4, 0, 9, 1, 4, 2, 2, 9, 5, 2, 2, 6, 1, 7, 6, 8, 0, 1, 4, 3, 7, 3, 5, 6, 7, 6, 3, 3, 1, 2, 4, 8, 8, 7, 8, 6, 2, 3, 5, 4, 6, 8, 4, 9, 9, 7, 9, 7, 8, 7, 4, 8, 3, 4, 8, 3, 8, 1, 3, 8, 6, 2, 0, 3, 8, 3, 1, 5, 1, 7, 6, 7, 7, 3, 7, 9, 7, 2, 8, 5, 6, 9, 1, 0, 8, 9, 2, 6, 2, 5, 8, 3, 2, 1 (list; constant; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

e/2 = lim n -> infinity n*(e-(1+1/n)^n) - Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 17 2002

An unusual infinite product for this number: e/2=prod ((1/n)!)^mu(n), for n from 1 to infinity, where mu is the Mobius function (see Millane ref.). [John M. Campbell (jmaxwellcampbell(AT)gmail.com), June 14 2011]

REFERENCES

Jolley, Summation of Series, Dover (1961) eq. (161) on page 30.

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,20000

R. P. Millane., A product form of the Möbius transform, Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, USA.

FORMULA

10*this constant = 5*exp(1) = sum_{j=0..infinity} j^3/j! [Jolley] - R. J. Mathar, Oct 03 2011

EXAMPLE

1.359140914229522617680143735676331248878623546849979787483483813862038... = A001113/2. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 10 2009]

MATHEMATICA

N[Product[((1/n)!)^MoebiusMu[n], {n, 1, 200000}]] ( * From John M. Campbell, June 14 2011 * )

PROG

(PARI) { default(realprecision, 20080); x=exp(1)/2; for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b019739.txt", n, " ", d)); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 10 2009]

CROSSREFS

Cf. A006083 = Continued fraction. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 10 2009]

Sequence in context: A058642 A141251 A186190 * A101298 A200510 A138055

Adjacent sequences:  A019736 A019737 A019738 * A019740 A019741 A019742

KEYWORD

nonn,cons

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

Fixed my PARI program, had -n Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 19 2009

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Last modified February 14 05:09 EST 2012. Contains 205570 sequences.