Riordan array (1/(1-2*x), x*C(x)) where C(x) is the o.g.f. of Catalan numbers A000108.

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =3a(5) =1a(6) =8a(7) =8a(8) =4a(9) =1a(10) =16a(11) =21a(12) =13a(13) =5a(14) =1a(15) =32a(16) =56a(17) =40a(18) =19a(19) =6a(20) =1a(21) =64a(22) =154a(23) =122a(24) =66a(25) =26a(26) =7a(27) =1a(28) =128a(29) =440