G.f. satisfies: A(A(x)) = Sum_{n>=1} A(x)^(n(n+1)/2)/x^(n(n-1)/2).

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =43a(6) =144a(7) =519a(8) =1986a(9) =8016a(10) =34019a(11) =151136a(12) =700137a(13) =3374510a(14) =16884773a(15) =87496596a(16) =468797414a(17) =2593125476a(18) =14783179194a(19) =86749832134a(20) =523386747685