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A154943 Decimal expansion of the negated value of the sum_q [log(1-1/q)+1/q] over the semiprimes q. 0
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 (list; constant; graph; refs; listen; history; text; internal format)
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

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Last modified July 8 08:08 EDT 2020. Contains 335520 sequences. (Running on oeis4.)