A258644 Fourth arithmetic derivative of n.

0, 0, 0, 0, 4, 0, 0, 0, 80, 0, 0, 0, 176, 0, 1, 32, 368, 0, 1, 0, 112, 0, 0, 0, 240, 0, 16, 27, 368, 0, 0, 0, 752, 5, 0, 80, 272, 0, 1, 176, 220, 0, 0, 0, 608, 80, 1, 0, 1552, 5, 32, 48, 272, 0, 540, 176, 560, 0, 0, 0, 560, 0, 6, 44, 7168, 7, 0, 0, 284, 12, 0

Offset

0,5

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Formula

a(n) = A003415^4(n).

Maple

d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]):
A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
a:= n-> A(n, 4):
seq(a(n), n=0..70);

Crossrefs

Column k=4 of A258651.

Cf. A003415.

Sequence in context: A099306 A228630 A174647 * A169770 A287633 A222931

Adjacent sequences: A258641 A258642 A258643 * A258645 A258646 A258647

Keyword

nonn,look

Author

Alois P. Heinz, Jun 06 2015

Status

approved