Triangle T(n,k) read by rows: (1/n) * C(2n+k,k-1) * C(n,k); n, k >= 1.

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =8a(5) =12a(6) =1a(7) =15a(8) =55a(9) =55a(10) =1a(11) =24a(12) =156a(13) =364a(14) =273a(15) =1a(16) =35a(17) =350a(18) =1400a(19) =2380a(20) =1428a(21) =1a(22) =48a(23) =680a(24) =4080a(25) =11628a(26) =15504a(27) =7752a(28) =1a(29) =63