Irregular triangle read by rows: the W-transformation of the Catalan triangle A033184.

Terms

a(0) =1a(1) =2a(2) =4a(3) =1a(4) =10a(5) =4a(6) =20a(7) =21a(8) =1a(9) =56a(10) =70a(11) =6a(12) =140a(13) =238a(14) =50a(15) =1a(16) =420a(17) =792a(18) =210a(19) =8a(20) =1176a(21) =2604a(22) =990a(23) =91a(24) =1a(25) =3696a(26) =8778a(27) =3850a(28) =462a(29) =10