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%I #16 Mar 24 2023 17:09:47
%S 2,3,2,5,5,7,2,3,7,11,5,13,9,4,2,17,5,19,7,5,13,23,5,5,15,3,9,29,3,31,
%T 2,7,19,6,5,37,21,8,7,41,3,43,13,4,25,47,5,7,7,10,15,53,5,8,9,11,31,
%U 59,3,61,33,5,2,9,3,67,19,13,5,71,5,73,39,4,21,9,3
%N a(n) is the numerator of the median of the distinct prime factors of n.
%H Winston de Greef, <a href="/A361630/b361630.txt">Table of n, a(n) for n = 2..10000</a>
%F For p a prime, a(p^k) = p.
%e a(12) = 5 since the distinct prime factors of 12 are 2 and 3, of median equal to 5/2.
%e a(30) = 3 since the distinct prime factors of 30 are 2, 3, and 5, of median equal to 3.
%t a[n_]:=Numerator[Median[FactorInteger[n][[All, 1]]]]; Array[a,77,2]
%o (PARI) a(n)=my(f=factor(n)[,1]~, i=length(f)); numerator(if(i%2, f[i\2+1], (f[i/2]+f[i/2+1])/2)) \\ _Winston de Greef_, Mar 23 2023
%Y Cf. A001221, A027748, A323171, A361565, A361631 (denominator), A361632 (with multiplicity).
%K nonn,frac
%O 2,1
%A _Stefano Spezia_, Mar 18 2023
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