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%I A258852 #7 Jun 25 2015 08:03:34
%S A258852 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,
%T A258852 135,64,11,16,5,208,12,11,13,188,20,41,64,188,6,21,15,192,88,13,19,
%U A258852 448,116,86,58,108,32,351,49,156,53,56,7,260,33,16,332,704,73
%N A258852 Second pi-based arithmetic derivative of n.
%H A258852 Alois P. Heinz, <a href="/A258852/b258852.txt">Table of n, a(n) for n = 0..10000</a>
%F A258852 a(n) = A258851^2(n).
%F A258852 a(A258862(n)) = n.
%p A258852 with(numtheory):
%p A258852 d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):
%p A258852 A:= proc(n, k) option remember; `if`(k=0, n, d(A(n, k-1))) end:
%p A258852 a:= n-> A(n, 2):
%p A258852 seq(a(n), n=0..100);
%Y A258852 Column k=2 of A258850.
%Y A258852 Cf. A000720, A258851, A258862.
%K A258852 nonn
%O A258852 0,5
%A A258852 _Alois P. Heinz_, Jun 12 2015

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