OFFSET
1,1
REFERENCES
Steven R. Finch, Mathematical Constants, Cambridge, 2003, Section 2.7. Euler Totient Constants, pp. 115-119.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
Steven R. Finch, Errata and Addenda to Mathematical Constants, arXiv:2001.00578 [math.HO], 2020, p. 16.
Kevin Ford, The distribution of Totients
FORMULA
1/(1 - rho), where rho is A246746.
EXAMPLE
2.186263464885754808050867579590101743875879953801252477564664456821...
MATHEMATICA
digits = 98; F[x_?NumericQ] := NSum[((k+1)*Log[k+1] - k*Log[k] - 1)*x^k, {k, 1, Infinity}, WorkingPrecision -> digits + 10, NSumTerms -> 1000]; rho = x /. FindRoot[F[x] == 1, {x, 1/2, 3/5}, WorkingPrecision -> digits + 10]; RealDigits[1/(1 - rho), 10, digits] // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, May 12 2016
STATUS
approved