A243584 Decimal expansion of 1/(eta*P'(eta)), a constant related to the asymptotic evaluation of the number of prime multiplicative compositions, where eta is A243350, the unique solution of P(x)=1, P being the prime zeta P function (P(x) = sum_(p prime) 1/p^x).

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

Offset

0,1

References

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.5 Kalmar's composition constant, p. 293.

Links

Table of n, a(n) for n=0..29.

Eric Weisstein's MathWorld, Prime Zeta function

Example

0.41277323709367...

Mathematica

digits = 30; eta = x /. FindRoot[PrimeZetaP[x] == 1, {x, 7/5},  WorkingPrecision -> digits + 200]; c = N[1/(eta*PrimeZetaP'[eta]) // Re, digits + 200]; RealDigits[c, 10, digits ] // First (* updated Sep 11 2015 *)

Crossrefs

Cf. A243350.

Sequence in context: A141332 A241184 A241185 * A084460 A216863 A120578

Adjacent sequences: A243581 A243582 A243583 * A243585 A243586 A243587

Keyword

nonn,cons,more

Author

Jean-François Alcover, Jun 06 2014

Status

approved