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A065474 Decimal expansion of Feller-Tornier constant: Product_{p prime} (1 - 2/p^2). 15
3, 2, 2, 6, 3, 4, 0, 9, 8, 9, 3, 9, 2, 4, 4, 6, 7, 0, 5, 7, 9, 5, 3, 1, 6, 9, 2, 5, 4, 8, 2, 3, 7, 0, 6, 6, 5, 7, 0, 9, 5, 0, 5, 7, 9, 6, 6, 5, 8, 3, 2, 7, 0, 9, 9, 6, 1, 8, 1, 1, 2, 5, 2, 4, 5, 3, 2, 5, 0, 0, 6, 3, 4, 8, 6, 2, 4, 4, 6, 0, 9, 8, 8, 4, 5, 2, 3, 4, 8, 1, 5, 6, 8, 5, 6, 3, 7, 5, 5, 2, 1, 7, 7, 2, 7, 3 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Density of A007674, squarefree n such that n + 1 is squarefree. - Charles R Greathouse IV, Aug 10 2011

LINKS

Table of n, a(n) for n=0..105.

H. Cohen, High precision computation of Hardy-Littlewood constants.

R. J. Mathar, Hardy-Littlewood constants embedded into infinite products over all positive integers, arXiv:0903.2514 [math.NT], 2009-2011, constant F_1^(2).

G. Niklasch, Some number theoretical constants: 1000-digit values [Cached copy]

Eric Weisstein's World of Mathematics, Squarefree

Eric Weisstein's World of Mathematics, Prime Products

Zack Wolske, Number Fields with Large Minimal Index, Ph.D. Thesis, University of Toronto, 2018.

EXAMPLE

0.322634098939244670579531692548...

MATHEMATICA

$MaxExtraPrecision = 800; digits = 98; terms = 800; P[n_] := PrimeZetaP[n]; LR = Join[{0, 0}, LinearRecurrence[{0, 2}, {-4, 0}, terms + 10]]; r[n_Integer] := LR[[n]]; Exp[NSum[r[n]*P[n - 1]/(n - 1), {n, 3, terms}, NSumTerms -> terms, WorkingPrecision -> digits + 10]] // RealDigits[#, 10, digits]& // First (* Jean-Fran├žois Alcover, Apr 18 2016 *)

CROSSREFS

Cf. A007674, A058026, A065493, A074893.

Sequence in context: A285733 A106335 A218698 * A272332 A197586 A111702

Adjacent sequences:  A065471 A065472 A065473 * A065475 A065476 A065477

KEYWORD

cons,nonn

AUTHOR

N. J. A. Sloane, Nov 19 2001

EXTENSIONS

Edited by Dean Hickerson, Sep 10 2002

More digits from Vaclav Kotesovec, Dec 18 2019

STATUS

approved

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Last modified January 27 21:50 EST 2020. Contains 331300 sequences. (Running on oeis4.)