G.f. satisfies: A(x) = x + A(x^2/(1-x)^2).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =17a(6) =38a(7) =88a(8) =208a(9) =497a(10) =1194a(11) =2877a(12) =6948a(13) =16821a(14) =40846a(15) =99539a(16) =243536a(17) =598353a(18) =1476370a(19) =3657883a(20) =9098420a(21) =22713077a(22) =56887062a(23) =142897576a(24) =359879600a(25) =908373713a(26) =2297266554a(27) =5819357841a(28) =14762051140a(29) =37491373173