G.f. A(x) satisfies: A(x) = 1 + x^2 + x^3 * A(x/(1 - x)) / (1 - x).

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =2a(6) =5a(7) =12a(8) =28a(9) =68a(10) =181a(11) =531a(12) =1671a(13) =5491a(14) =18627a(15) =65299a(16) =237880a(17) =903907a(18) =3580619a(19) =14729777a(20) =62639952a(21) =274442521a(22) =1236730244a(23) =5729809348a(24) =27292248240a(25) =133614280479a(26) =671803041553