Triangle of central coefficients of generalized Pascal-Narayana triangles.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =1a(7) =6a(8) =3a(9) =1a(10) =1a(11) =20a(12) =20a(13) =4a(14) =1a(15) =1a(16) =70a(17) =175a(18) =50a(19) =5a(20) =1a(21) =1a(22) =252a(23) =1764a(24) =980a(25) =105a(26) =6a(27) =1a(28) =1a(29) =924