A389076 Sum of all other divisors of primeshifted n except its squarefree part: a(n) = sigma(A003961(n)) - A007913(A003961(n)).

0, 1, 1, 12, 1, 9, 1, 37, 30, 11, 1, 73, 1, 15, 13, 120, 1, 121, 1, 97, 17, 17, 1, 225, 56, 21, 151, 145, 1, 87, 1, 361, 19, 23, 19, 402, 1, 27, 23, 299, 1, 123, 1, 169, 241, 33, 1, 721, 132, 225, 25, 217, 1, 609, 21, 447, 29, 35, 1, 589, 1, 41, 361, 1092, 25, 141, 1, 241, 35, 153, 1, 1237, 1, 45, 337, 289, 25

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to prime indices in the factorization of n.

Index entries for sequences related to sigma(n).

Formula

a(n) = A326126(A003961(n)).

a(n) = A003973(n) - A003961(A007913(n)).

Prog

(PARI)
A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A326126(n) = (sigma(n)-core(n));
A389076(n) = A326126(A003961(n));

Crossrefs

Cf. A003961, A003973, A007913, A326126, A389077, A389078.

Sequence in context: A318489 A121985 A245839 * A068329 A334074 A010215

Adjacent sequences: A389073 A389074 A389075 * A389077 A389078 A389079

Keyword

nonn

Author

Antti Karttunen, Sep 23 2025

Status

approved