%I #8 Mar 28 2014 17:16:18

%S 1,2,2,3,2,5,3,2,2,7,2,3,2,11,5,2,2,13,2,2,3,3,2,17,2,7,19,2,3,2,2,23,

%T 2,5,2,3,2,29,2,31,2,2,3,2,5,2,11,37,2,3,2,41,2,2,43,2,3,2,2,3,13,47,

%U 2,7,2,3,2,2,53,2,5,5,2,3,2,3,59,2,61,2,3,2,5,2,67,2,3,2,17,71,2,73,2,3

%N Smallest prime factor of n-th perfect power.

%C a(n) = A020639(A001597(n)).

%H Reinhard Zumkeller, <a href="/A076396/b076396.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PerfectPower.html">Perfect Powers</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/LeastPrimeFactor.html">Least Prime Factor</a>.

%F a(n) = A020639(A025478(n)).

%o (Haskell)

%o a076396 = a020639 . a025478 -- _Reinhard Zumkeller_, Mar 28 2014

%Y Cf. A025478, A076397, A076403.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Oct 09 2002