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A065469 Decimal expansion of product(1 - 1/(p^2-1)), p prime >= 2). 2

%I

%S 5,3,0,7,1,1,8,2,0,4,7,2,0,4,4,7,9,4,9,7,2,9,4,3,7,7,2,4,7,2,9,7,7,1,

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

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

%N Decimal expansion of product(1 - 1/(p^2-1)), p prime >= 2).

%H G. Niklasch, <a href="/A001692/a001692.html">Some number theoretical constants: 1000-digit values</a> [Cached copy]

%F Product of A013661 by A065474. - R. J. Mathar, Mar 26 2011

%e 0.53071182047204479497294377247...

%t $MaxExtraPrecision = 800; digits = 98; terms = 800; P[n_] := PrimeZetaP[n]; LR = LinearRecurrence[{0, 3, 0, -2}, {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-Fran├žois Alcover_, Apr 18 2016 *)

%Y Cf. A072101.

%K cons,nonn

%O 0,1

%A _N. J. A. Sloane_, Nov 19 2001

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Last modified March 20 15:43 EDT 2019. Contains 321345 sequences. (Running on oeis4.)