Riordan array ((1-2*x)/(1-3*x+x^2), x/(1-3*x+x^2)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =1a(6) =5a(7) =13a(8) =7a(9) =1a(10) =13a(11) =40a(12) =33a(13) =10a(14) =1a(15) =34a(16) =120a(17) =132a(18) =62a(19) =13a(20) =1a(21) =89a(22) =354a(23) =483a(24) =308a(25) =100a(26) =16a(27) =1a(28) =233a(29) =1031