Sum of the divisors of binomial(2n,n).

Terms

a(0) =3a(1) =12a(2) =42a(3) =144a(4) =728a(5) =2688a(6) =10080a(7) =39312a(8) =127008a(9) =423360a(10) =2419200a(11) =6773760a(12) =32140800a(13) =160704000a(14) =626745600a(15) =1940889600a(16) =9289728000a(17) =38397542400a(18) =156332851200a(19) =642477588480