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A258852
Second pi-based arithmetic derivative of n.
3
0, 0, 0, 1, 4, 2, 4, 4, 20, 20, 5, 3, 32, 7, 19, 8, 80, 4, 37, 12, 80, 25, 26, 12, 76, 53, 30, 135, 64, 11, 16, 5, 208, 12, 11, 13, 188, 20, 41, 64, 188, 6, 21, 15, 192, 88, 13, 19, 448, 116, 86, 58, 108, 32, 351, 49, 156, 53, 56, 7, 260, 33, 16, 332, 704, 73
OFFSET
0,5
LINKS
FORMULA
a(n) = A258851^2(n).
a(A258862(n)) = 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, 2):
seq(a(n), n=0..100);
CROSSREFS
Column k=2 of A258850.
Sequence in context: A061469 A222641 A368437 * A021706 A224183 A131953
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 12 2015
STATUS
approved