Triangle T(n,m) = Sum_{k=0..m} Catalan(n-k)*Catalan(k).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =3a(5) =5a(6) =5a(7) =7a(8) =9a(9) =14a(10) =14a(11) =19a(12) =23a(13) =28a(14) =42a(15) =42a(16) =56a(17) =66a(18) =76a(19) =90a(20) =132a(21) =132a(22) =174a(23) =202a(24) =227a(25) =255a(26) =297a(27) =429a(28) =429a(29) =561