A258863 - OEIS

%I #8 Aug 31 2015 21:19:55

%S 0,1,1,2,-1,4,-3,8,0,-1,-6,15,-14,9,4,13,-25,26,-25,24,-6,-5,-12,43,

%T -22,-5,29,-10,-34,43,-42,69,-43,-6,10,43,-72,23,9,40,-71,60,-59,50,

%U 23,-46,-26,113,-72,29,-30,21,-60,119,-77,58,-54,-13,-32,119,-118

%N First differences of the pi-based arithmetic derivative sequence A258851.

%H Alois P. Heinz, <a href="/A258863/b258863.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = A258851(n+1) - A258851(n).

%p with(numtheory):

%p d:= n-> n*add(i[2]*pi(i[1])/i[1], i=ifactors(n)[2]):

%p a:= n-> d(n+1)-d(n):

%p seq(a(n), n=0..100);

%Y Cf. A000720, A258851.

%K sign,look

%O 0,4

%A _Alois P. Heinz_, Jun 12 2015