OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
Will Nicholes, Prime Signatures
EXAMPLE
From Petros Hadjicostas, Oct 26 2019: (Start)
a(1) = (2^3)*(3^2)*5*7*11 = 27720;
a(2) = (2^3)*(3^2)*5*7*13 = 32760;
a(3) = (2^2)*(3^3)*5*7*11 = 41580;
a(4) = (2^3)*(3^2)*5*7*17 = 42840;
a(5) = (2^3)*3*(5^2)*7*11 = 46200.
(End)
MATHEMATICA
f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 1, 2, 3}; Select[Range[150000], f]
PROG
(PARI) list(lim)=my(v=List(), t1, t2, t3, t4); forprime(p=2, sqrtnint(lim\420, 3), t1=p^3; forprime(q=2, sqrtint(lim\(30*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2, lim\(6*t2), if(r==p || r==q, next); t3=r*t2; forprime(s=2, lim\(2*t3), if(s==p || s==q || s==r, next); t4=s*t3; forprime(t=2, lim\t4, if(t==p || t==q || t==r || t==s, next); listput(v, t4*t)))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, May 04 2011
STATUS
approved