A336567 Sum of proper divisors of {n divided by its largest squarefree divisor}.

0, 0, 0, 1, 0, 0, 0, 3, 1, 0, 0, 1, 0, 0, 0, 7, 0, 1, 0, 1, 0, 0, 0, 3, 1, 0, 4, 1, 0, 0, 0, 15, 0, 0, 0, 6, 0, 0, 0, 3, 0, 0, 0, 1, 1, 0, 0, 7, 1, 1, 0, 1, 0, 4, 0, 3, 0, 0, 0, 1, 0, 0, 1, 31, 0, 0, 0, 1, 0, 0, 0, 16, 0, 0, 1, 1, 0, 0, 0, 7, 13, 0, 0, 1, 0, 0, 0, 3, 0, 1, 0, 1, 0, 0, 0, 15, 0, 1, 1, 8, 0, 0, 0, 3, 0

Offset

1,8

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Formula

a(n) = A001065(A003557(n)).

a(n) = A335341(n) - A003557(n) = A336563(n) / A007947(n).

Prog

(PARI)
A007947(n) = factorback(factorint(n)[, 1]);
A057723(n) = { my(r=A007947(n)); (r*sigma(n/r)); };
A336563(n) = (A057723(n)-n);
A336567(n) = (A336563(n)/A007947(n));

Crossrefs

Cf. A000203, A001065, A003557, A007947, A057723, A335341, A336563.

Sequence in context: A144209 A094544 A062734 * A361902 A205531 A269246

Adjacent sequences: A336564 A336565 A336566 * A336568 A336569 A336570

Keyword

nonn

Author

Antti Karttunen, Jul 27 2020

Status

approved