cp's OEIS Frontend

A326044 a(n) = n - {the largest square dividing its sum of divisors}: a(n) = n - A008833(sigma(n)).

%I A326044 #7 Jun 05 2019 21:53:29
%S A326044 0,1,-1,3,4,2,3,7,8,1,7,8,12,10,11,15,8,17,15,19,5,-14,19,20,24,25,23,
%T A326044 24,28,-6,15,23,17,25,19,35,36,34,35,31,40,26,39,40,44,10,31,44,48,49,
%U A326044 15,3,44,50,19,52,41,49,55,56,60,46,59,63,61,-78,63,59,53,-74,35,71,72,73,71,72,61,74,63,79,-40
%N A326044 a(n) = n - {the largest square dividing its sum of divisors}: a(n) = n - A008833(sigma(n)).
%H A326044 Antti Karttunen, <a href="/A326044/b326044.txt">Table of n, a(n) for n = 1..20000</a>
%H A326044 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A326044 a(n) = n - A326039(n) = n - A008833(A000203(n)).
%F A326044 a(n) = A033879(n) + A326045(n).
%o A326044 (PARI)
%o A326044 A008833(n) = (n/core(n));
%o A326044 A326039(n) = A008833(sigma(n));
%o A326044 A326044(n) = (n-A326039(n));
%Y A326044 Cf. A000203, A008833, A033879, A326039, A326045, A326046.
%K A326044 sign
%O A326044 1,4
%A A326044 _Antti Karttunen_, Jun 05 2019