Triangular table of 2^n *(n+k)! / ((n-k)! * k! * 4^k).

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =6a(5) =3a(6) =8a(7) =24a(8) =30a(9) =15a(10) =16a(11) =80a(12) =180a(13) =210a(14) =105a(15) =32a(16) =240a(17) =840a(18) =1680a(19) =1890a(20) =945a(21) =64a(22) =672a(23) =3360a(24) =10080a(25) =18900a(26) =20790a(27) =10395a(28) =128a(29) =1792