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%I #10 Apr 01 2020 22:18:14
%S 1,2,3,4,7,11,19,38
%N Number of different prime factors of the smallest n-perfect number.
%H Achim Flammenkamp, <a href="http://wwwhomes.uni-bielefeld.de/achim/mpn.html">The Multiply Perfect Numbers Page</a>.
%F a(n) = A001221(A007539(n)).
%e a(4)=4 because the smallest 4-perfect number factorization is 2^5*3^3*5*7, which has 4 different prime factors.
%Y Cf. A001221, A007539, A107482.
%K nonn,hard,more
%O 1,2
%A Jose Brox (tautocrona(AT)terra.es), May 27 2005
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