OFFSET
1,1
COMMENTS
Note that the Hardy-Ramanujan is the first and the smallest repeated number: a(3)=a(6)=1729.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1) = 2*3*5 = 30
a(2) = 3*5*7 = 105
a(3) = 7*13*19 = 1729
a(4) = 5*13*17 = 1105
a(5) = 11*31*41 = 13981
PROG
(PARI) a(n)=my(p, q, k=1); while(!isprime(k+=n), ); p=k; while(!isprime(k+=n), ); q=k; while(!isprime(k+=n), ); p*q*k \\ Charles R Greathouse IV, Sep 03 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Sep 02 2011
STATUS
approved