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A258644
Fourth arithmetic derivative of n.
4
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
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
KEYWORD
nonn,look
AUTHOR
Alois P. Heinz, Jun 06 2015
STATUS
approved