Denominator of Cotesian number C(n,2).

Terms

a(0) =6a(1) =8a(2) =15a(3) =144a(4) =280a(5) =640a(6) =14175a(7) =2240a(8) =199584a(9) =87091200a(10) =875875a(11) =22353408000a(12) =5003856000a(13) =229605376a(14) =10854718875