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A373368 a(n) = gcd(n, A059975(n)), where A059975 is fully additive with a(p) = p-1.

%I A373368 #9 Jun 05 2024 14:49:48
%S A373368 1,1,1,2,1,3,1,1,1,5,1,4,1,7,3,4,1,1,1,2,1,11,1,1,1,13,3,4,1,1,1,1,3,
%T A373368 17,5,6,1,19,1,1,1,3,1,4,1,23,1,6,1,1,3,2,1,1,1,1,1,29,1,4,1,31,1,2,1,
%U A373368 1,1,2,3,1,1,1,1,37,5,4,1,3,1,8,1,41,1,2,5,43,3,1,1,9,1,4,1,47,1,1,1,1,1,10
%N A373368 a(n) = gcd(n, A059975(n)), where A059975 is fully additive with a(p) = p-1.
%H A373368 Antti Karttunen, <a href="/A373368/b373368.txt">Table of n, a(n) for n = 1..65537</a>
%o A373368 (PARI)
%o A373368 A059975(n) = {my(f = factor(n)); sum(i = 1, #f~, f[i, 2]*(f[i, 1] - 1)); };
%o A373368 A373368(n) = gcd(n, A059975(n));
%Y A373368 Cf. A059975, A108269 (positions of even terms), A359794 (of odd terms), A359832 (parity of terms).
%Y A373368 Cf. also A082299, A373361, A373369.
%K A373368 nonn
%O A373368 1,4
%A A373368 _Antti Karttunen_, Jun 05 2024