Series reversion of x/(1 + 2*x + 3*x^2 + x^3).

Terms

a(0) =0a(1) =1a(2) =2a(3) =7a(4) =27a(5) =114a(6) =507a(7) =2342a(8) =11125a(9) =54002a(10) =266684a(11) =1335610a(12) =6767477a(13) =34629709a(14) =178701317a(15) =928903447a(16) =4859345882a(17) =25563551782a(18) =135153617840a(19) =717740916202