G.f. satisfies: A(x) = Sum_{n>=0} x^(n^2) * A(x)^(n^2).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =6a(6) =16a(7) =36a(8) =75a(9) =164a(10) =401a(11) =1046a(12) =2718a(13) =6878a(14) =17200a(15) =43486a(16) =112202a(17) =293540a(18) =770535a(19) =2019891a(20) =5296670a(21) =13942944a(22) =36902130a(23) =98097968a(24) =261456388a(25) =697970447a(26) =1866383507a(27) =5001333169a(28) =13432923544a(29) =36154294520