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A154928 Decimal expansion of sum_{q in A001358} log(q)/q^2 over the semiprimes q = 4,6,9,... 1
2, 8, 3, 6, 0, 6, 8, 1, 5, 4, 0, 7, 9, 8, 0, 6, 5, 2, 2, 2, 4, 2, 5, 8, 2, 2, 2, 5, 4, 8, 2, 7, 8, 3, 3, 6, 0, 7, 9, 3, 5, 0, 5, 7, 8, 2, 3, 7, 8, 1, 4, 0, 1, 3, 4, 1, 1, 1, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Semiprime analog of A136271. The absolute value of the first derivative of the semiprime zeta function at 2.

LINKS

Table of n, a(n) for n=0..58.

R. J. Mathar, Series of reciprocal powers of k-almost primes, arXiv:0803.0900 [math.NT], Table 4.

FORMULA

Equals sum_{i=1,2,..,infinity} log(A001358(i))/A074985(i) .

EXAMPLE

Equals 0.283606815... = log(4)/16+log(6)/36+log(9)/81+....

CROSSREFS

Sequence in context: A243340 A173823 A222296 * A201394 A169844 A076123

Adjacent sequences:  A154925 A154926 A154927 * A154929 A154930 A154931

KEYWORD

cons,nonn

AUTHOR

R. J. Mathar, Jan 17 2009

STATUS

approved

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Last modified December 19 09:54 EST 2014. Contains 252186 sequences.