A345049 - OEIS

%I #4 Jun 07 2021 06:50:52

%S -1,0,-2,3,-12,10,-30,11,2,20,-90,40,-132,30,16,31,-240,48,-306,104,0,

%T 50,-462,112,-36,60,26,192,-756,344,-870,79,-80,80,-240,158,-1260,90,

%U -144,312,-1560,636,-1722,440,216,110,-2070,280,-162,152,-320,600,-2652,186,-880,600,-432,140,-3306,1120,-3540,150,348,191

%N a(n) = A173557(n) * A345001(n).

%F a(n) = A173557(n) * A345001(n).

%F a(n) = A345048(n) - A345050(n).

%o (PARI)

%o A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));

%o A173557(n) = factorback(apply(p -> p-1,factor(n)[,1]));

%o A345001(n) = (sigma(n)+A003415(n)-(2*n));

%o A345049(n) = (A173557(n) * A345001(n));

%Y Cf. A173557, A345001, A345048, A345050, A345051.

%K sign

%O 1,3

%A _Antti Karttunen_, Jun 06 2021