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%I #19 Jun 20 2022 14:45:24
%S 1,1,2,3,2,2,2,1,1,2,2,1,2,2,4,5,2,1,2,3,4,2,2,1,3,2,4,3,2,4,2,3,4,2,
%T 4,1,2,2,4,1,2,4,2,3,2,2,2,5,3,3,4,3,2,4,4,1,4,2,2,1,2,2,2,7,4,4,2,3,
%U 4,4,2,1,2,2,2,3,4,4,2,1,5,2,2,1,4,2,4,1,2,2,4,3,4,2,4,1,2,3,2,9,2,4,2,1,8
%N Numerator of d(n)/n, where d(n) (A000005) is the number of divisors of n.
%C Values of n at which k first occurs, for k >= 1: 1, 3, 4, 15, 16, 175, 64, 105, 100, 567, 1024, 1925, 4096, 3645, 784, 945, 65536, ... - _Robert G. Wilson v_, Feb 04 2004. [Is this A136641? - Editors]
%H Antti Karttunen, <a href="/A090387/b090387.txt">Table of n, a(n) for n = 1..65537</a>
%e a(6)=2 because the number of divisors of 6 is 4 and 4 divided by 6 equals 2/3, which has 2 as its numerator.
%p with(numtheory): seq(numer(tau(n)/n), n=1..105) ; # _Zerinvary Lajos_, Jun 04 2008
%o (PARI) A090387(n) = numerator(numdiv(n)/n); \\ _Antti Karttunen_, Sep 25 2018
%o (Python)
%o from math import gcd
%o from sympy import divisor_count
%o def A090387(n): return (d := divisor_count(n))//gcd(n,d) # _Chai Wah Wu_, Jun 20 2022
%Y Cf. A000005, A090395 (denominators), A136641.
%K easy,frac,nonn
%O 1,3
%A Ivan_E_Mayle(AT)a_provider.com, Jan 31 2004
%E More terms from _Robert G. Wilson v_, Feb 04 2004