Row sums of Riordan array ((1-3x+x^2)/(1-4x+3x^2), x(1-2x)/(1-4x+3x^2)).

Terms

a(0) =1a(1) =2a(2) =6a(3) =20a(4) =70a(5) =250a(6) =900a(7) =3250a(8) =11750a(9) =42500a(10) =153750a(11) =556250a(12) =2012500a(13) =7281250a(14) =26343750a(15) =95312500a(16) =344843750a(17) =1247656250a(18) =4514062500a(19) =16332031250a(20) =59089843750a(21) =213789062500a(22) =773496093750