A272531 Decimal expansion of C_2 (so named by S. Finch), a constant which is an analog of Niven's constant when mean of exponents is considered instead of maximum.

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

Offset: 0

Author

Jean-François Alcover, May 02 2016

Keywords

• nonn
• cons

Examples

			0.1187309349576408430176668841155338623125786669962548878395960878789...
		

References

• Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 2.2 Meissel-Mertens constants (pp. 94-95) and Section 2.6 Niven's constant p.112.

Links

• Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 15.
• Eric Weisstein's MathWorld, Niven's Constant

Crossrefs

Cf. A033150, A077761, A085548, A136141.

Programs

Mathematica

digits = 100;
C1 = NSum[PrimeZetaP[n], {n, 2, Infinity}, WorkingPrecision -> digits + 10, NSumTerms -> 2*digits] ;
M = EulerGamma - NSum[PrimeZetaP[n]/n, {n, 2, Infinity}, WorkingPrecision -> digits + 10, NSumTerms -> 3*digits] ;
N0 = PrimeZetaP[2];
C2 = C1 (1 - M) - N0;
RealDigits[C2, 10, digits][[1]]

Formula

C_2 = C_1 (1 - M) - N, using Finch's notation, where C_1 is A136141, M A077761 and N A085548.