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A258854
Fourth pi-based arithmetic derivative of n.
2
0, 0, 0, 0, 4, 0, 4, 4, 80, 80, 2, 1, 208, 4, 12, 20, 512, 4, 20, 32, 512, 53, 30, 32, 324, 32, 16, 864, 704, 3, 80, 2, 2304, 32, 3, 7, 460, 80, 6, 704, 460, 4, 25, 8, 2432, 228, 7, 12, 6720, 332, 20, 56, 1188, 208, 3888, 116, 424, 32, 156, 4, 956, 12, 80, 764
OFFSET
0,5
LINKS
FORMULA
a(n) = A258851^4(n).
MAPLE
with(numtheory):
d:= n-> n*add(i[2]*pi(i[1])/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..100);
CROSSREFS
Column k=4 of A258850.
Sequence in context: A110854 A278086 A021716 * A258855 A258856 A258857
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 12 2015
STATUS
approved