cp's OEIS Frontend

A326188 a(n) = A001065(n) - A003557(n), where A001065(n) = the sum of proper divisors of n, and A003557(n) = n divided by its largest squarefree divisor.

%I A326188 #11 Jul 12 2019 07:21:39
%S A326188 -1,0,0,1,0,5,0,3,1,7,0,14,0,9,8,7,0,18,0,20,10,13,0,32,1,15,4,26,0,
%T A326188 41,0,15,14,19,12,49,0,21,16,46,0,53,0,38,30,25,0,68,1,38,20,44,0,57,
%U A326188 16,60,22,31,0,106,0,33,38,31,18,77,0,56,26,73,0,111,0,39,44,62,18,89,0,98,13,43,0,138,22,45,32,88,0,141,20
%N A326188 a(n) = A001065(n) - A003557(n), where A001065(n) = the sum of proper divisors of n, and A003557(n) = n divided by its largest squarefree divisor.
%H A326188 Antti Karttunen, <a href="/A326188/b326188.txt">Table of n, a(n) for n = 1..16384</a>
%H A326188 Antti Karttunen, <a href="/A326188/a326188.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%F A326188 a(n) = A326187(n) - n = A000203(n) - A003557(n) - n.
%F A326188 a(n) = A001065(n) - A003557(n).
%o A326188 (PARI)
%o A326188 A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557
%o A326188 A326188(n) = ((sigma(n)-A003557(n))-n);
%Y A326188 Cf. A000203, A001065, A003557, A010848, A326187, A326189.
%Y A326188 Cf. also A326185.
%K A326188 sign
%O A326188 1,6
%A A326188 _Antti Karttunen_, Jul 11 2019