%I #6 Nov 25 2014 00:00:47
%S 1,4,9,4,25,4,49,4,9,4,121,4,169,4,9,4,289,4,361,4,9,4,529,4,25,4,9,4,
%T 841,4,961,4,9,4,25,4,1369,4,9,4,1681,4,1849,4,9,4,2209,4,49,4,9,4,
%U 2809,4,25,4,9,4,3481,4,3721,4,9,4,25,4,4489,4,9,4,5041,4,5329,4,9,4
%N (Smallest prime-factor of n)^2.
%C a(n) = A000290(A020639(n)).
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/LeastPrimeFactor.html">Least Prime Factor</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SquareNumber.html">Square Number</a>
%Y Cf. A088378, A088379.
%Y Cf. A068319.
%Y Cf. A247180.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Sep 28 2003