OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
Will Nicholes, Prime Signatures
MATHEMATICA
f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 4, 4}; Select[Range[250000], f]
PROG
(PARI) list(lim)=my(v=List(), t1, t2); forprime(p=2, (lim\2)^(1/8), t1=p^4; forprime(q=p+1, (lim\t1)^(1/4), t2=t1*q^4; forprime(r=2, lim\t2, if(p==r||q==r, next); listput(v, t2*r)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 24 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, May 04 2011
STATUS
approved