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%I #5 Nov 19 2014 10:27:47
%S 1,1,1,1,5,1,1,1,7,1,5,1,9,4,1,1,5,1,7,5,13,1,5,1,15,1,9,1,31,1,1,7,
%T 19,6,5,1,21,8,7,1,41,1,13,4,25,1,5,1,7,10,15,1,5,8,9,11,31,1,31,1,33,
%U 5,1,9,61,1,19,13,59,1,5,1,39,4,21,9,71,1,7
%N Denominator of the harmonic mean of the prime factors, without multiplicity, of n.
%H Colin Barker, <a href="/A250097/b250097.txt">Table of n, a(n) for n = 2..1000</a>
%e a(6) = 5 because the distinct prime factors of 6 are [2,3] and 2 / (1/2+1/3) = 12/5.
%o (PARI)
%o harmonicmean(v) = #v / sum(k=1, #v, 1/v[k])
%o a(n) = denominator(harmonicmean(factorint(n)~[1,]))
%o vector(100, n, a(n+1))
%Y Cf. A250096.
%K nonn
%O 2,5
%A _Colin Barker_, Nov 12 2014