A339719 - OEIS

%I #5 Dec 14 2020 16:00:57

%S 1,-4,-4,6,-4,12,-4,-8,6,12,-4,-12,-4,12,12,17,-4,-12,-4,-12,12,12,-4,

%T 20,6,12,-8,-12,-4,-20,-4,-28,12,12,12,10,-4,12,12,20,-4,-20,-4,-12,

%U -12,12,-4,-48,6,-12,12,-12,-4,20,12,20,12,12,-4,4,-4,12,-12,38,12,-20,-4,-12,12,-20

%N Dirichlet g.f.: Product_{k>=2} 1 / (1 + k^(-s))^4.

%F a(1) = 1; a(n) = -Sum_{d|n, d < n} A339336(n/d) * a(d).

%F a(p^k) = A022599(k) for prime p.

%Y Cf. A022599, A316441, A339336, A339717, A339718, A339720, A339721, A339722.

%K sign

%O 1,2

%A _Ilya Gutkovskiy_, Dec 14 2020