cp's OEIS Frontend

A294885 a(n) = A004125(n) mod n = [Sum_{i=1..n} (n mod i)] mod n.

%I A294885 #9 Jul 10 2024 18:38:53
%S A294885 0,0,1,1,4,3,1,0,3,3,0,5,2,3,6,4,0,11,7,1,7,11,6,13,3,8,17,12,6,18,12,
%T A294885 7,19,27,8,18,11,20,35,18,10,32,24,20,24,36,27,38,22,20,41,38,28,6,34,
%U A294885 16,40,56,45,46,35,52,0,53,23,65,53,51,12,65,52,60,47,68,6,4,48,22,7,46,73,15,82,11,58,83,35,15,87,17,71,71
%N A294885 a(n) = A004125(n) mod n = [Sum_{i=1..n} (n mod i)] mod n.
%H A294885 Antti Karttunen, <a href="/A294885/b294885.txt">Table of n, a(n) for n = 1..16384</a>
%F A294885 a(n) = [Sum_{i=1..n} (n mod i)] mod n.
%t A294885 Table[Mod[Sum[Mod[n,i],{i,n}],n],{n,100}] (* _Harvey P. Dale_, Jul 10 2024 *)
%o A294885 (PARI) A294885(n) = (sum(k=2, n, n%k)%n);
%Y A294885 Cf. A004125.
%Y A294885 Cf. A056550 (positions of zeros).
%K A294885 nonn
%O A294885 1,5
%A A294885 _Antti Karttunen_, Nov 13 2017