Riordan array (c(x)/(1+x*c(x)), x*c(x)), c(x) the g.f. of A000108.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =2a(9) =1a(10) =6a(11) =8a(12) =6a(13) =3a(14) =1a(15) =18a(16) =24a(17) =18a(18) =10a(19) =4a(20) =1a(21) =57a(22) =75a(23) =57a(24) =33a(25) =15a(26) =5a(27) =1a(28) =186a(29) =243