Dirichlet g.f.: Sum_{n>0} a(n)/n^s = zeta(s-1)*zeta(s-3)/(zeta(s-2))^2.

Terms

a(0) =1a(1) =2a(2) =12a(3) =20a(4) =80a(5) =24a(6) =252a(7) =168a(8) =360a(9) =160a(10) =1100a(11) =240a(12) =1872a(13) =504a(14) =960a(15) =1360a(16) =4352a(17) =720a(18) =6156a(19) =1600a(20) =3024a(21) =2200a(22) =11132a(23) =2016a(24) =10400a(25) =3744a(26) =9828a(27) =5040a(28) =22736a(29) =1920