A394007 Decimal expansion of zeta(3)^2 * Product_{p prime} (1 - 1/p^2 - 2/p^3 + 2/p^4).

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

Offset

0,1

Comments

The asymptotic probability that two cubefree numbers selected independently at random are coprime.

Links

Table of n, a(n) for n=0..104.

Formula

Equals zeta(3)^2 * A394006.

Equals Product_{p prime} (1 - ((p+1)/(p^2+p+1))^2).

Example

0.676360626983496754089102877222555507544109873453869...

Prog

(PARI) zeta(3)^2 * prodeulerrat(1 - 1/p^2 - 2/p^3 + 2/p^4)

Crossrefs

Cf. A002117, A004709, A065472, A088453, A394006.

Sequence in context: A239134 A196616 A369104 * A253271 A258945 A120962

Adjacent sequences: A394004 A394005 A394006 * A394008 A394009 A394010

Keyword

nonn,cons

Author

Amiram Eldar, Mar 06 2026

Status

approved