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} 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
KEYWORD
cons,nonn
AUTHOR
R. J. Mathar, Jan 17 2009
STATUS
approved