A394043 Decimal expansion of Product_{p prime} (1 - 1/(p^2*(p^2+p-1)^2)).

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

Offset

0,1

Comments

The asymptotic probability that the greatest common divisor of two exponentially odd numbers (A268335) selected independently at random is a squarefree number (A005117).

Links

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

Formula

Equals A394044 / A065463^2.

Example

0.989036472451736591408650561334465956483936443399124...

Prog

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

Crossrefs

Cf. A005117, A065463, A268335, A394041, A394044.

Sequence in context: A175572 A263984 A021095 * A090998 A163930 A157371

Adjacent sequences: A394040 A394041 A394042 * A394044 A394045 A394046

Keyword

nonn,cons

Author

Amiram Eldar, Mar 08 2026

Status

approved