%I #16 Sep 07 2020 06:29:45

%S 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,4,1,1,

%T 1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,8,1,1,1,1,

%U 1,1,1,1,1,1,1,1,1,1,1,2,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1,4,1,1,1,1,1,1,1,1,1

%N n divided by largest 4th-power-free factor of n.

%H Antti Karttunen, <a href="/A062379/b062379.txt">Table of n, a(n) for n = 1..10000</a>

%H Henry Bottomley, <a href="http://fs.gallup.unm.edu/Bottomley-Sm-Mult-Functions.htm">Some Smarandache-type multiplicative sequences</a>.

%F a(n) = n/A058035(n).

%F Multiplicative with a(p^e) = p^max(e-3, 0). - _Amiram Eldar_, Sep 07 2020

%t f[p_, e_] := p^Max[e-3, 0]; a[n_] := Times @@ (f @@@ FactorInteger[n]); Array[a, 100] (* _Amiram Eldar_, Sep 07 2020 *)

%o (Scheme)

%o (define (A062379 n) (/ n (A058035 n)))

%o (define (A058035 n) (if (= 1 n) n (* (expt (A020639 n) (min 3 (A067029 n))) (A058035 (A028234 n)))))

%o ;; _Antti Karttunen_, Sep 13 2017

%Y Cf. A000190, A000583, A008835, A053164, A053165, A053166, A053167, A056553, A056554, A056555, A058035. See A003557 for squares and A062378 for cubes.

%K nonn,mult

%O 1,16

%A _Henry Bottomley_, Jun 18 2001