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

Terms

a(0) =1a(1) =2a(2) =4a(3) =10a(4) =24a(5) =62a(6) =156a(7) =408a(8) =1048a(9) =2758a(10) =7164a(11) =18922a(12) =49488a(13) =131016a(14) =344208a(15) =912720a(16) =2405496a(17) =6385814a(18) =16868604a(19) =44818494a(20) =118595064a(21) =315299694a(22) =835423164a(23) =2222185344a(24) =5894038944a(25) =15684059112