Triangle read by rows: T(n,m) = Sum_{i=1..n} C(n,i-m)*C(n+m-i,i-1)*C(n+m-i,m)/n, with T(0,0)=1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =2a(7) =5a(8) =4a(9) =1a(10) =4a(11) =13a(12) =15a(13) =7a(14) =1a(15) =9a(16) =35a(17) =52a(18) =36a(19) =11a(20) =1a(21) =21a(22) =96a(23) =175a(24) =160a(25) =75a(26) =16a(27) =1a(28) =51a(29) =267