Expansion of (1/x) * Series_Reversion( x / (1+x+x^3)^2 ).

Terms

a(0) =1a(1) =2a(2) =5a(3) =16a(4) =60a(5) =242a(6) =1014a(7) =4370a(8) =19278a(9) =86678a(10) =395751a(11) =1829742a(12) =8549100a(13) =40302810a(14) =191469165a(15) =915751966a(16) =4405727502a(17) =21307102900a(18) =103526683797a(19) =505118705078