A154943 - OEIS

A154943

Decimal expansion of the negated value of the sum_q [log(1-1/q)+1/q] over the semiprimes q.

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

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OFFSET

0,2

COMMENTS

The semiprime analog of A143524. Taylor expansion of the logarithm shows that the value is sum_{s=2,3,..,infinity} P_2(s)/s, where P_2(s) are the semiprime zeta functions in Table 3 of the preprint arXiv:0803.0900. P_2(2)=A117543 and P_2(3)=0.023806..., P_2(4)=0.004994... etc.

LINKS

Table of n, a(n) for n=0..53.

FORMULA

Equals the negative of Sum_{i>=1} ( log(1-1/A001358(i)) +1/A001358(i)).

EXAMPLE

Equals 0.079848040306232691897402254...

CROSSREFS

Sequence in context: A259069 A209328 A228049 * A126041 A319881 A021560

Adjacent sequences: A154940 A154941 A154942 * A154944 A154945 A154946

KEYWORD

cons,nonn

AUTHOR

R. J. Mathar, Jan 17 2009

STATUS

approved