Denominator of Sum_{i=1..n} 1/(i*C(2*i,i)).

Terms

a(0) =1a(1) =2a(2) =12a(3) =5a(4) =280a(5) =2520a(6) =220a(7) =120120a(8) =144144a(9) =1361360a(10) =25865840a(11) =77597520a(12) =22881320a(13) =371821450a(14) =11473347600a(15) =9242418900a(18) =281488407200