OFFSET
1,2
COMMENTS
The setting a(1)=1 is conventional.
Upper bound (for any n): a(n) <= (3^(1/3))^n = A002581^n.
LINKS
Stanislav Sykora, Table of n, a(n) for n = 1..2000
FORMULA
For prime p, a(p)=p.
For n>1: When gpf(n)>3 then a(n)=gpf(n)^(n/gpf(n)); otherwise if n is even then a(n)=2^(n/2); otherwise a(n)=3^(n/3).
If n is in A033845, a(n) = 2^(n/2); otherwise a(n) = gpf(n)^(n/gpf(n)). - Franklin T. Adams-Watters, Jun 15 2014
EXAMPLE
a(12)=64 because 2^(12/2)=64 is smaller than 3^(12/3)=81.
PROG
(PARI) A243405(n)= {my(m, k, p, q); if(n==1, return(1));
p=factor(n); m=2^n;
for(k=1, #p[, 1], q=p[k, 1]^(n\p[k, 1]); if(q<m, m=q));
return (m); }
CROSSREFS
KEYWORD
nonn
AUTHOR
Stanislav Sykora, Jun 04 2014
STATUS
approved