OFFSET
1,2
COMMENTS
If p is a prime then a(p) = prime(p)^(p-1).
No entry is zero for n>1, since prime(n)^(n-1) has exactly n divisors. When n is not prime, this will generally be greater than a(n), but it suffices to prove existence. - Franklin T. Adams-Watters, May 14 2014
PROG
(PARI) a(n) = {if (n==1, return (0)); if (isprime(n), return (prime(n)^(n-1))); np = prime(n); mnp = np; while (numdiv(mnp) != n, mnp += np; ); return (mnp); } \\ Michel Marcus, Mar 19 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Oct 21 2002
EXTENSIONS
Corrected and extended by Sascha Kurz, Jan 22 2003
More terms from Michel Marcus, Mar 19 2013
STATUS
approved