A389078 Primeshifted n minus its squarefree part: a(n) = A003961(n) - A007913(A003961(n)).

0, 0, 0, 8, 0, 0, 0, 24, 24, 0, 0, 40, 0, 0, 0, 80, 0, 72, 0, 56, 0, 0, 0, 120, 48, 0, 120, 88, 0, 0, 0, 240, 0, 0, 0, 224, 0, 0, 0, 168, 0, 0, 0, 104, 168, 0, 0, 400, 120, 144, 0, 136, 0, 360, 0, 264, 0, 0, 0, 280, 0, 0, 264, 728, 0, 0, 0, 152, 0, 0, 0, 672, 0, 0, 240, 184, 0, 0, 0, 560, 624, 0, 0, 440, 0, 0, 0

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.

Formula

a(n) = A326128(A003961(n)).

Prog

(PARI)
A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A326128(n) = (n-core(n));
A389078(n) = A326128(A003961(n));

Crossrefs

Cf. A000203, A003961, A007913, A326128.

Cf. also A389076, A389077.

Sequence in context: A028705 A028608 A028600 * A299165 A221890 A047758

Adjacent sequences: A389075 A389076 A389077 * A389079 A389080 A389081

Keyword

nonn

Author

Antti Karttunen, Sep 23 2025

Status

approved