A065481 - OEIS

A065481

Decimal expansion of Product_{p prime} (1 - 1/(p^2-2)).

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

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OFFSET

0,1

LINKS

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

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

EXAMPLE

0.38894518997956192931157878976445...

MATHEMATICA

$MaxExtraPrecision = 2000; digits = 98; terms = 2000; P[n_] := PrimeZetaP[n ]; LR = LinearRecurrence[{0, 5, 0, -6}, {0, 0, -2, 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-François Alcover, Apr 18 2016 *)

PROG

(PARI) prodeulerrat(1 - 1/(p^2-2)) \\ Amiram Eldar, Mar 15 2021

CROSSREFS

Cf. A065178, A078076.

Sequence in context: A332892 A371137 A140975 * A354222 A032538 A168209

Adjacent sequences: A065478 A065479 A065480 * A065482 A065483 A065484

KEYWORD

cons,nonn

AUTHOR

N. J. A. Sloane, Nov 19 2001

STATUS

approved