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.

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, 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, 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

Offset

1,8

Links

Antti Karttunen, Table of n, a(n) for n = 1..100000

Formula

a(n) = gcd(A000203(n), A001414(n)).

a(n) = gcd(A000203(n), A086665(n)) = gcd(A001414(n), A086665(n)).

Prog

(PARI)
A001414(n) = ((n=factor(n))[, 1]~*n[, 2]);
A374126(n) = gcd(A001414(n), sigma(n));

Crossrefs

Cf. A000203, A001414, A086665.

Sequence in context: A140670 A293682 A276651 * A185587 A068845 A324910

Adjacent sequences: A374123 A374124 A374125 * A374127 A374128 A374129

Keyword

nonn

Author

Antti Karttunen, Jul 06 2024

Status

approved