OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
The 28th positive integer divisible by exactly an odd number of distinct primes is 60. 60 is factored as 2^2*3*5. The distinct primes dividing 60 are therefore 2, 3, and 5. Since the middle of these primes is 3, then a(28) = 3.
MATHEMATICA
mp[n_]:=Module[{prs=Transpose[FactorInteger[n]][[1]], pos}, pos= Floor[ Length[ prs]/2]+1; prs[[pos]]]; mp/@Select[Range[300], OddQ[PrimeNu[#]]&] (* Harvey P. Dale, Jun 20 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Mar 16 2010
EXTENSIONS
More terms from R. J. Mathar, Oct 09 2010
STATUS
approved