Numerator of Cotesian number C(n,2).

Terms

a(0) =1a(1) =3a(2) =2a(3) =25a(4) =9a(5) =49a(6) =-464a(7) =27a(8) =-16175a(9) =-3237113a(10) =-105387a(11) =-1737125143a(12) =-770720657a(13) =-25881785a(14) =-1997012608a(16) =-214182958293