cp's OEIS Frontend

A374126 a(n) = gcd(sigma(n), sopfr(n)), where sigma is the sum of divisors, and sopfr is the sum of prime factors with repetition.

%I A374126 #6 Jul 06 2024 11:06:14
%S A374126 1,1,1,1,1,1,1,3,1,1,1,7,1,3,8,1,1,1,1,3,2,1,1,3,1,3,1,1,1,2,1,1,2,1,
%T A374126 12,1,1,3,8,1,1,12,1,3,1,1,1,1,1,3,4,1,1,1,8,1,2,1,1,12,1,3,13,1,6,16,
%U A374126 1,21,2,2,1,3,1,3,1,1,6,6,1,1,1,1,1,14,2,3,8,1,1,13,4,3,2,1,24,1,1,1,1,7,1,2
%N A374126 a(n) = gcd(sigma(n), sopfr(n)), where sigma is the sum of divisors, and sopfr is the sum of prime factors with repetition.
%H A374126 Antti Karttunen, <a href="/A374126/b374126.txt">Table of n, a(n) for n = 1..100000</a>
%F A374126 a(n) = gcd(A000203(n), A001414(n)).
%F A374126 a(n) = gcd(A000203(n), A086665(n)) = gcd(A001414(n), A086665(n)).
%o A374126 (PARI)
%o A374126 A001414(n) = ((n=factor(n))[, 1]~*n[, 2]);
%o A374126 A374126(n) = gcd(A001414(n), sigma(n));
%Y A374126 Cf. A000203, A001414, A086665.
%K A374126 nonn
%O A374126 1,8
%A A374126 _Antti Karttunen_, Jul 06 2024