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

Terms

a(0) =1a(1) =1a(2) =1a(3) =6a(4) =11a(5) =51a(6) =106a(7) =492a(8) =1115a(9) =5317a(10) =12912a(11) =62283a(12) =159146a(13) =767083a(14) =2036260a(15) =9765849a(16) =26735811a(17) =127447531a(18) =358219288a(19) =1696410364a(20) =4879284508a(21) =22946311567a(22) =67362378507a(23) =314520916727a(24) =940422623222