The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 3 05:55 EDT 2020. Contains 336197 sequences. (Running on oeis4.)