Triangle read by rows. T(n, k) = binomial(3*n - 1, 3*k - 1).

Terms

a(0) =1a(1) =10a(2) =1a(3) =28a(4) =56a(5) =1a(6) =55a(7) =462a(8) =165a(9) =1a(10) =91a(11) =2002a(12) =3003a(13) =364a(14) =1a(15) =136a(16) =6188a(17) =24310a(18) =12376a(19) =680a(20) =1a(21) =190a(22) =15504a(23) =125970a(24) =167960a(25) =38760a(26) =1140a(27) =1a(28) =253a(29) =33649