OFFSET
1,2
COMMENTS
The fraction of substituents which become isolated in a simple polymer model is 1/10 this number, see Flory 1939 (and 1936). - Charles R Greathouse IV, Nov 30 2012
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..2000
Paul J. Flory, Intramolecular reaction between neighboring substituents of vinyl polymers, Journal of the American Chemical Society 61:6 (1939), pp. 1518-1521.
Paul J. Flory, Molecular size distribution in linear condensation polymers, Journal of the American Chemical Society 58:10 (1936), pp. 1877-1885.
Ovidiu Furdui, From Lalescu's sequence to a Gamma function limit, Gazette of the Australian Mathematical Society, Vol. 35, No. 5 (2008), pp. 339-344.
FORMULA
1/(2*e) = Integral_{x=1..oo} e^(-x^2) * x dx. - Amiram Eldar, Aug 03 2020
1/(2*e) = lim_{n->oo} n * ((n+1)!^(1/(n+1)) - n!^(1/n) - 1/e) (Furdui, 2008). - Amiram Eldar, Apr 20 2023
EXAMPLE
5/e = 1.839397205857211607977618850807304337229...
1/(2*e) = 0.1839397205857211607977618850807304337229... (see Greathouse's comment).
MATHEMATICA
RealDigits[5/E , 10, 50][[1]] (* G. C. Greubel, Sep 16 2016 *)
PROG
(PARI) 5/exp(1) \\ Michel Marcus, Sep 17 2016
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Omar E. Pol, Nov 15 2007
STATUS
approved