A335204 Decimal expansion of Product_{p = prime} (1 + 6/p^2).

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

Offset: 1

Author

Jude Thaddeus Poole Jr., Andrew Hinton, Reid Huntley, May 26 2020

Keywords

• nonn
• cons

Examples

			6.95743589392521746246609006782918530413...
		

Links

• Pieter Moree, Approximation of singular series and automata, manuscripta mathematica, Vol. 101 (2000), pp. 385-399.
• Wikipedia, Euler Product.

Crossrefs

Cf. A000040, A001248, A082020, A065474, A206256, A328017.

Programs

Mathematica

$MaxExtraPrecision = 10000; Do[Print[5/2*Exp[-N[Sum[(-1)^j*6^j*(PrimeZetaP[2*j] - 1/4^j)/j, {j, 1, t}], 120]]], {t, 100, 1000, 100}] (* Vaclav Kotesovec, May 29 2020 *)

PARI

prodeulerrat(1 + 6/p^2) \\ Amiram Eldar, Mar 17 2021

Extensions

More terms from Vaclav Kotesovec, May 29 2020