OFFSET
1,1
FORMULA
Conjecturally, a(n) ~ sqrt(n log log n / (log n)^3). - Charles R Greathouse IV, Jun 29 2011
EXAMPLE
a(1)=2 because 2 and 3 are in range [semiprime(1)-sqrt(semiprime(1)), semiprime(1))=[2, 4).
MAPLE
A192393 := proc(n) local phi, plo; phi := A001358(n)-1 ; plo := ceil(A001358(n) -sqrt(A001358(n)))-1 ; numtheory[pi](phi)-numtheory[pi](plo) ; end proc: # R. J. Mathar, Jul 12 2011
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Juri-Stepan Gerasimov, Jun 29 2011
EXTENSIONS
Corrected by R. J. Mathar, Jul 12 2011
STATUS
approved