OFFSET
1,1
COMMENTS
LINKS
Zak Seidov, Table of n, a(n) for n = 1..1000
MATHEMATICA
semiPrimeQ[n_] := Plus @@ Last /@ FactorInteger@ n == 2; f[n_] := Min@ Select[ Divisors@ n, semiPrimeQ] /. {\[Infinity] -> 0}; f /@ Rest@ Select[ Range@ 112, !PrimeQ@ # &]
Reap[Do[If[! PrimeQ[n], Sow[Select[Divisors[n], PrimeOmega[#] == 2 &][[1]]]], {n, 4, 1200}]][[2, 1]] (* Zak Seidov, Mar 18 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 12 2003
STATUS
approved