A326045 - OEIS

%I #5 Jun 05 2019 21:53:36

%S -1,0,-3,2,0,2,-3,6,3,-1,-3,12,0,6,5,14,-8,20,-3,21,-5,-22,-3,32,5,15,

%T 9,24,0,6,-15,22,-1,11,-3,54,0,18,13,41,0,38,-3,36,32,-10,-15,72,7,42,

%U -15,-3,-8,62,-19,60,7,23,-3,104,0,18,37,62,15,-66,-3,49,11,-70,-35,122,0,39,45,60,3,86,-15,105,-81,35,-3

%N a(n) is the sum of divisors of n, minus the largest square dividing that sum, minus n: a(n) = sigma(n) - A008833(sigma(n)) - n.

%H Antti Karttunen, <a href="/A326045/b326045.txt">Table of n, a(n) for n = 1..20000</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%F a(n) = A326040(n) - n = sigma(n) - A008833(sigma(n)) - n.

%o (PARI)

%o A008833(n) = (n/core(n));

%o A326039(n) = A008833(sigma(n));

%o A326040(n) = (sigma(n)-A008833(sigma(n)));

%o A326045(n) = (A326040(n)-n);

%Y Cf. A000203, A008833, A326039, A326040, A326044, A326046.

%K sign

%O 1,3

%A _Antti Karttunen_, Jun 05 2019