Triangle read by rows: T(n,k) = binomial(n+1,k+1) * binomial(5*n-4*k+1,k) / (n+1), 0<=k<=n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =7a(5) =1a(6) =1a(7) =18a(8) =28a(9) =1a(10) =1a(11) =34a(12) =156a(13) =84a(14) =1a(15) =1a(16) =55a(17) =510a(18) =910a(19) =210a(20) =1a(21) =1a(22) =81a(23) =1265a(24) =4845a(25) =4095a(26) =462a(27) =1a(28) =1a(29) =112