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A073003 Decimal expansion of -exp(1)*Ei(-1), also called Gompertz's constant. +0
7
5, 9, 6, 3, 4, 7, 3, 6, 2, 3, 2, 3, 1, 9, 4, 0, 7, 4, 3, 4, 1, 0, 7, 8, 4, 9, 9, 3, 6, 9, 2, 7, 9, 3, 7, 6, 0, 7, 4, 1, 7, 7, 8, 6, 0, 1, 5, 2, 5, 4, 8, 7, 8, 1, 5, 7, 3, 4, 8, 4, 9, 1, 0, 4, 8, 2, 3, 2, 7, 2, 1, 9, 1, 1, 4, 8, 7, 4, 4, 1, 7, 4, 7, 0, 4, 3, 0, 4, 9, 7, 0, 9, 3, 6, 1, 2, 7, 6, 0, 3, 4, 4, 2, 3, 7 (list; cons; graph; listen)
OFFSET

0,1

COMMENT

0! - 1! + 2! - 3! + 4! - 5! + ... = (Borel) sum_{n=0}^infinity (-y)^n n! = KummerU(1,1,1/y)/y

Decimal expansion of phi(1) where phi(x)=integral(t=0,infinity, e^-t/(x+t) dt ). - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 11 2003

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Oct 16 2009: (Start)

The divergent series g(x=1,m) = 1^m*1! - 2^m*2! + 3^m*3! - 4^m*4! + ... , m=>-1, is intimately related to Gompertz's constant. We discovered that g(x=1,m) = (-1)^m * (A040027(m) - A000110(m+1) * A073003) with A000110 the Bell numbers and A040027 a sequence that was published by Gould, see for more information A163940.

(End)

REFERENCES

Bruce C. Berndt, Ramanujan's notebooks Part II, Springer, p. 171

Bruce C. Berndt, Ramanujan's notebooks Part I, Springer, p. 144-145.

Walls, H. S., Analytic Theory of Continued Fractions, Van Nostrand, New York, 1948, p. 356

LINKS

Simon Plouffe, -exp(1)*Ei(-1)

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics

Eric Weisstein's World of Mathematics, Exponential Integral

A. I. Aptekarev, On linear forms containing the Euler constant, arXiv:0902.1768 [math.NT]. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 14 2009]

G.H. Hardy, Divergent Series , Oxford University Press, 1949. p. 29. [From Johannes W. Meijer (meijgia(AT)hotmail.com), Oct 16 2009]

Ed Sandifer, Divergent Series, How Euler Did It, MAA Online, June 2006. [From Johannes W. Meijer (meijgia(AT)hotmail.com), Oct 16 2009]

FORMULA

phi(1)=e*(sum(k>=1, (-1)^(k-1)/k/k!) - Gamma)=0.596347362323194... where Gamma is the Euler constant.

G = 0.596347... = 1/(1+1/(1+1/(1+2/(1+2/(1+3/(1+3/(1+4/(1+4/(1+5/(1+5/(1+6/(...- Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Aug 14 2005

EXAMPLE

0.59634736232319407434...

MATHEMATICA

RealDigits[ N[ -Exp[1]*ExpIntegralEi[ -1], 110]] [[1]]

CROSSREFS

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Oct 16 2009: (Start)

Equals A001113*A099285.

(End)

Sequence in context: A134879 A051158 A117605 this_sequence A087498 A121060 A021630

Adjacent sequences: A073000 A073001 A073002 this_sequence A073004 A073005 A073006

KEYWORD

cons,nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 03 2002

EXTENSIONS

Additional references from Gerald McGarvey (Gerald.McGarvey(AT)comcast.net), Oct 10 2005

Link corrected by Johannes W. Meijer (meijgia(AT)hotmail.com), Aug 01 2009

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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