cp's OEIS Frontend

A340070 a(n) = gcd(A003415(n), A069359(n)).

%I A340070 #10 Dec 31 2020 08:20:23
%S A340070 0,1,1,2,1,5,1,4,3,7,1,2,1,9,8,8,1,3,1,2,10,13,1,4,5,15,9,2,1,31,1,16,
%T A340070 14,19,12,30,1,21,16,4,1,41,1,2,3,25,1,8,7,5,20,2,1,9,16,4,22,31,1,2,
%U A340070 1,33,3,32,18,61,1,2,26,59,1,12,1,39,5,2,18,71,1,8,27,43,1,2,22,45,32,4,1,3,20,2,34,49,24
%N A340070 a(n) = gcd(A003415(n), A069359(n)).
%H A340070 Antti Karttunen, <a href="/A340070/b340070.txt">Table of n, a(n) for n = 1..65537</a>
%F A340070 a(n) = gcd(A003415(n), A069359(n)) = gcd(A003415(n), A329039(n)).
%F A340070 For all squarefree k, a(k) = A003415(k) = A069359(k).
%o A340070 (PARI)
%o A340070 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
%o A340070 A069359(n) = (n*sumdiv(n, d, isprime(d)/d)); \\ From A069359
%o A340070 A340070(n) = gcd(A003415(n), A069359(n));
%Y A340070 Cf. A003415, A005117, A069359, A329039.
%Y A340070 Cf. also A085731, A300253, A327858.
%K A340070 nonn
%O A340070 1,4
%A A340070 _Antti Karttunen_, Dec 30 2020