Dirichlet g.f.: zeta(s-1) / (zeta(s) * zeta(s-2)).

Terms

a(0) =1a(1) =-3a(2) =-7a(3) =-2a(4) =-21a(5) =21a(6) =-43a(7) =-4a(8) =-12a(9) =63a(10) =-111a(11) =14a(12) =-157a(13) =129a(14) =147a(15) =-8a(16) =-273a(17) =36a(18) =-343a(19) =42a(20) =301a(21) =333a(22) =-507a(23) =28a(24) =-80a(25) =471a(26) =-36a(27) =86a(28) =-813a(29) =-441