OFFSET
1,2
COMMENTS
See A052854.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 45.
Ph. Flajolet, É. Fusy, X. Gourdon, D. Panario, N. Pouyanne, A Hybrid of Darboux's Method and Singularity Analysis in Combinatorial Asymptotics, arXiv:math/0606370 [math.CO], 2006.
FORMULA
exp(sum_{k>=1} 1/(2*k)*(1 - sqrt(1 - 4^(1 - k))).
EXAMPLE
1.7160305349222819640474643990422120919697678373178634631868194...
MAPLE
evalf(exp(sum(1/(2*k)*(1-sqrt(1-4^(1-k))), k=1..infinity)), 100); # Vaclav Kotesovec, Sep 17 2014
MATHEMATICA
digits = 76; K = Exp[NSum[1/(2 k)*(1 - Sqrt[1 - 4^(1 - k)]), {k, 1, Infinity}, WorkingPrecision -> digits + 10, NSumTerms -> 100]]; RealDigits[K, 10, digits] // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Sep 08 2014
EXTENSIONS
More terms from Vaclav Kotesovec, Sep 17 2014
STATUS
approved