Triangle read by rows: T(n, k) = binomial(n, k)*binomial(2*n+k, k), 0 <= k <= n.

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =10a(5) =15a(6) =1a(7) =21a(8) =84a(9) =84a(10) =1a(11) =36a(12) =270a(13) =660a(14) =495a(15) =1a(16) =55a(17) =660a(18) =2860a(19) =5005a(20) =3003a(21) =1a(22) =78a(23) =1365a(24) =9100a(25) =27300a(26) =37128a(27) =18564a(28) =1a(29) =105