OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
dpeQ[n_]:=Module[{exps=Transpose[FactorInteger[n]][[2]]}, CompositeQ[n] && Length[ Union[exps]]==Length[exps]&&AllTrue[exps, PrimeQ]]; Select[ Range[ 3500], dpeQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 02 2016 *)
PROG
(PARI) isok(n) = {nbf = omega(n); f = factor(n); for (i = 1, nbf, if (! isprime(f[i, 2]), return (0)); for (j = i+1, nbf, if (f[i, 2] == f[j, 2], return (0)); ); ); return (1); } \\ Michel Marcus, Aug 18 2013
(PARI) is(n)=if(n<4, return(0)); my(f=factor(n)[, 2]); vecmin(apply(isprime, f)) && #Set(f)==#f \\ Charles R Greathouse IV, Sep 08 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Jon Wild, Feb 14 2006
STATUS
approved