A246061 - OEIS

A246061

Decimal expansion of lim_{n->infinity} ((1/log(n)^2)*Product_{2 < p < n, p prime} p/(p-2)).

1, 2, 0, 1, 3, 0, 3, 5, 5, 9, 9, 6, 7, 3, 6, 2, 2, 4, 1, 2, 4, 7, 5, 5, 5, 9, 5, 9, 2, 0, 7, 3, 8, 3, 4, 8, 2, 4, 5, 3, 8, 3, 8, 4, 4, 9, 4, 2, 7, 1, 1, 3, 0, 8, 5, 1, 8, 1, 9, 5, 5, 9, 7, 4, 1, 4, 8, 0, 0, 9, 9, 7, 7, 9, 4, 3, 7, 7, 5, 2, 2, 5, 9, 6, 7, 0, 6, 4, 3, 1, 8, 4, 8, 6, 1, 9, 7, 6, 0, 8, 8

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OFFSET

1,2

REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.1 Hardy-Littlewood constants, p. 86.

LINKS

Table of n, a(n) for n=1..101.

Eric Weisstein's MathWorld, Twin Primes Constant

FORMULA

Equals exp(2*EulerGamma)/(4*C_2), where C_2 is the twin primes constant A005597.

EXAMPLE

1.201303559967362241247555959207383482453838449427113...

MATHEMATICA

digits = 101; s[n_] := (1/n)* N[Sum[MoebiusMu[d]*2^(n/d), {d, Divisors[n]}], digits + 60]; C2 = (175/256)*Product[(Zeta[ n]*(1 - 2^(-n))*(1 - 3^(-n))*(1 - 5^(-n))*(1 - 7^(-n)))^(-s[ n]), {n, 2, digits + 60}]; RealDigits[Exp[2*EulerGamma]/(4*C2), 10, digits] // First

CROSSREFS

Cf. A005597.

Sequence in context: A172026 A296046 A060318 * A263730 A331533 A089994

Adjacent sequences: A246058 A246059 A246060 * A246062 A246063 A246064

KEYWORD

nonn,cons

AUTHOR

Jean-François Alcover, Sep 11 2014

STATUS

approved