A132120 Decimal expansion of the constant obtained through Pierce retro-expansion of the prime sequence.

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

Offset: 0

Author

R. J. Mathar, Oct 31 2007

Keywords

• cons
• nonn

Comments

The asymptotic density of numbers which have an odd number of the trailing zeros in their primorial base representation (A342050). - Amiram Eldar, Feb 28 2021

Examples

			0.3623062223664980487986263722240934618111798585344209997599510170278418863068...
		

Links

• Paolo P. Lava, Table of n, a(n) for n = 0..1000
• Eric Weisstein's World of Mathematics, Pierce Expansion.

Crossrefs

Cf. A064648, A342050.

Programs

Maple

Digits := 80 : a := 0 : for i from 1 to 100 do a := a+(-1.0)^(i-1)/mul(ithprime(j),j=1..i) ; print(a) ; od:

PARI

P=1; -sumalt(n=1,(-1)^n/P*=prime(n)) \\ Charles R Greathouse IV, Oct 03 2016

Formula

Equals Sum_{i>=1} (-1)^(i+1)/A002110(i).

Extensions

Corrected last entry by Paolo P. Lava, May 28 2013