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

Terms

a(0) =1a(1) =6a(2) =1a(3) =18a(4) =15a(5) =1a(6) =40a(7) =90a(8) =28a(9) =1a(10) =75a(11) =350a(12) =280a(13) =45a(14) =1a(15) =126a(16) =1050a(17) =1680a(18) =675a(19) =66a(20) =1a(21) =196a(22) =2646a(23) =7350a(24) =5775a(25) =1386a(26) =91a(27) =1a(28) =288a(29) =5880