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A084945
Decimal expansion of Golomb-Dickman constant.
25
6, 2, 4, 3, 2, 9, 9, 8, 8, 5, 4, 3, 5, 5, 0, 8, 7, 0, 9, 9, 2, 9, 3, 6, 3, 8, 3, 1, 0, 0, 8, 3, 7, 2, 4, 4, 1, 7, 9, 6, 4, 2, 6, 2, 0, 1, 8, 0, 5, 2, 9, 2, 8, 6, 9, 7, 3, 5, 5, 1, 9, 0, 2, 4, 9, 5, 6, 3, 8, 0, 8, 8, 8, 5, 5, 1, 1, 3, 2, 5, 4, 4, 6, 2, 4, 6, 0, 2, 7, 6, 1, 9, 5, 5, 3, 9, 8, 6, 8, 8, 6, 9
OFFSET
0,1
COMMENTS
The first 27 digits form a prime. - Jonathan Vos Post, Nov 12 2004
The first 1659 digits form a prime. - David Broadhurst, Apr 02 2010
The average number of digits in the largest prime factor of a random x-digit number is asymptotically x times this constant. - Charles R Greathouse IV, Jul 28 2015
Named after the American mathematician Solomon W. Golomb (1932 - 2016) and the Swedish actuary Karl Dickman (1861 - 1947). - Amiram Eldar, Aug 25 2020
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, pp. 284-287.
LINKS
David Broadhurst, PrimeForm message on the first 1659 digits, Apr 02 2010.
David Broadhurst, Titanic Golomb-Dickman prime, digest of 5 messages in primeform Yahoo group, Apr 2 - Apr 9, 2010. [Cached copy]
Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 171.
Solomon W. Golomb, Research Problem 11: Random permutations, Bull. Amer. Math. Soc. 70 (1964), p. 747.
Jeffrey C. Lagarias, Euler's constant: Euler's work and modern developments, Bull. Amer. Math. Soc., Vol. 50, No. 4 (2013), pp. 527-628, preprint, arXiv:1303.1856 [math.NT], 2013.
Andrew MacFie and Daniel Panario, Random Mappings with Restricted Preimages, in Progress in Cryptology-LATINCRYPT 2012, LNCS 7533, pp. 254-270, 2012. - From N. J. A. Sloane, Dec 25 2012
Simon Plouffe, The Golomb constant.
Eric Weisstein's World of Mathematics, Golomb-Dickman Constant.
FORMULA
From Amiram Eldar, Aug 25 2020: (Start)
Equals Integral_{x=0..1} exp(li(x)) dx, where li(x) is the logarithmic integral.
Equals Integral_{x=0..oo} exp(-x + Ei(-x)) dx, where Ei(x) is the exponential integral.
Equals Integral_{x=0..1} F(x/(1-x)) dx, where F(x) is the Dickman function. (End)
EXAMPLE
0.62432998854355087...
MAPLE
E1:= z-> int(exp(-t)/t, t=z..infinity):
lambda:= int(exp(-x-E1(x)), x=0..infinity):
s:= convert(evalf(lambda, 130), string):
seq(parse(s[n+1]), n=1..120); # Alois P. Heinz, Nov 20 2011
MATHEMATICA
NIntegrate[Exp[LogIntegral[x]], {x, 0, 1}, WorkingPrecision->110, MaxRecursion->20]
PROG
(PARI) intnum(x=0, 1-1e-9, exp(-eint1(-log(x)))) \\ Charles R Greathouse IV, Jul 28 2015
(PARI) default(realprecision, 103);
limitnum(n->intnum(x=0, 1-1/n, exp(-eint1(-log(x))))) \\ Gheorghe Coserea, Sep 26 2018
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Jun 13 2003
STATUS
approved