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A065474 Decimal expansion of Feller-Tornier constant: product(1 - 2/p^2, p prime). 14
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 (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

REFERENCES

H. Cohen, High precision computation of Hardy-Littlewood constants, http://www.math.u-bordeaux.fr/~cohen/hardylw.dvi

LINKS

Table of n, a(n) for n=0..97.

R. J. Mathar, Hardy-Littlewood constants embedded into infinite products over all positive integers, 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

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. A065493, A074893.

Sequence in context: A093055 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

STATUS

approved

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Last modified April 25 00:46 EDT 2017. Contains 285346 sequences.