Triangle T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = x + 2.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =12a(5) =4a(6) =8a(7) =52a(8) =52a(9) =8a(10) =16a(11) =196a(12) =416a(13) =196a(14) =16a(15) =32a(16) =684a(17) =2644a(18) =2644a(19) =684a(20) =32a(21) =64a(22) =2276a(23) =14680a(24) =26440a(25) =14680a(26) =2276a(27) =64a(28) =128a(29) =7340