Triangle of binomial(n,k)*(binomial(n+k,k)-binomial(n+k-2,k-1)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =4a(6) =1a(7) =9a(8) =21a(9) =14a(10) =1a(11) =16a(12) =66a(13) =100a(14) =50a(15) =1a(16) =25a(17) =160a(18) =410a(19) =455a(20) =182a(21) =1a(22) =36a(23) =330a(24) =1260a(25) =2310a(26) =2016a(27) =672a(28) =1a(29) =49