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A154937 Decimal expansion of sum_q 1/(q-1)^2 over the semiprimes q = 4,6,9,10,... 0
2, 0, 9, 7, 8, 8, 3, 2, 3, 9, 4, 0, 0, 1, 9, 4, 9, 2, 7, 5, 5, 3, 6, 8, 6, 0, 2, 4, 6, 9, 1, 8, 9, 2, 3, 6, 2, 6, 8, 6, 1, 3, 9, 3, 2, 9, 2, 1, 8, 5, 1, 3, 4, 3, 7, 5, 2, 8, 1, 7 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
Semiprime analog of A086242.
LINKS
R. J. Mathar, Series of reciprocal powers of k-almost primes, arXiv:0803.0900 [math.NT], Table 11.
FORMULA
Equals sum_{i=1,2,..,infinity) 1/(A001358(i)-1)^2.
EXAMPLE
Equals 0.2097883239400194927... = 1/3^2+1/5^2+1/8^2+1/9^2+1/13^2+...
CROSSREFS
Sequence in context: A021481 A029686 A083864 * A037996 A299626 A002741
KEYWORD
cons,nonn
AUTHOR
R. J. Mathar, Jan 17 2009
STATUS
approved

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Last modified April 15 00:51 EDT 2024. Contains 371667 sequences. (Running on oeis4.)