cp's OEIS Frontend

A331310 a(n) = gcd(n, A293442(n)).

%I A331310 #6 Jan 21 2020 18:22:42
%S A331310 1,2,1,1,1,2,1,2,3,2,1,6,1,2,1,1,1,6,1,2,1,2,1,12,1,2,3,2,1,2,1,2,1,2,
%T A331310 1,9,1,2,1,4,1,2,1,2,3,2,1,2,1,2,1,2,1,6,1,4,1,2,1,12,1,2,3,1,1,2,1,2,
%U A331310 1,2,1,18,1,2,3,2,1,2,1,10,1,2,1,12,1,2,1,4,1,6,1,2,1,2,1,4,1,2,3,1,1,2,1,4,1
%N A331310 a(n) = gcd(n, A293442(n)).
%H A331310 Antti Karttunen, <a href="/A331310/b331310.txt">Table of n, a(n) for n = 1..65537</a>
%F A331310 a(n) = gcd(n, A293442(n)).
%F A331310 A331310(n) = A331287(n) / A331311(n).
%o A331310 (PARI)
%o A331310 A019565(n) = {my(j,v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ From A019565
%o A331310 A293442(n) = factorback(apply(e -> A019565(e),factor(n)[,2]));
%o A331310 A331310(n) = gcd(n, A293442(n));
%Y A331310 Cf. A019565, A293442, A331287, A331311.
%K A331310 nonn
%O A331310 1,2
%A A331310 _Antti Karttunen_, Jan 20 2020