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A065471
Decimal expansion of Product_{p prime} (1 - 1/(p^2*(p^2-1))).
3
9, 0, 1, 9, 2, 6, 0, 3, 9, 5, 8, 7, 0, 8, 2, 1, 7, 1, 3, 7, 7, 7, 1, 5, 2, 0, 2, 5, 5, 0, 4, 7, 1, 9, 3, 4, 1, 5, 2, 5, 5, 5, 4, 5, 3, 1, 5, 5, 5, 5, 5, 3, 5, 8, 3, 5, 8, 4, 3, 3, 3, 2, 7, 2, 8, 9, 2, 9, 3, 7, 8, 1, 0, 7, 2, 5, 6, 8, 1, 5, 7, 5, 2, 3, 8, 9, 0, 4, 9, 9, 9, 0, 1, 0, 3, 3, 8, 0
OFFSET
0,1
EXAMPLE
0.90192603958708217137771520255047...
MATHEMATICA
$MaxExtraPrecision = 500; digits = 98; terms = 500; P[n_] := PrimeZetaP[n]; LR = Join[{0, 0, 0, 0}, LinearRecurrence[{0, 2, 0, 0, 0, -1}, {-4, 0, -6, 0, -12, 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*(p^2-1))) \\ Amiram Eldar, Mar 16 2021
CROSSREFS
Sequence in context: A200488 A249418 A256036 * A310000 A199284 A189186
KEYWORD
cons,nonn
AUTHOR
N. J. A. Sloane, Nov 19 2001
STATUS
approved