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

Terms

a(0) =1a(1) =2a(2) =7a(3) =24a(4) =83a(5) =290a(6) =1023a(7) =3640a(8) =13052a(9) =47124a(10) =171190a(11) =625328a(12) =2295561a(13) =8464690a(14) =31339455a(15) =116458200a(16) =434217000a(17) =1623971580a(18) =6090823890a(19) =22903571280a(20) =86332453350a(21) =326145976884