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

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =9a(5) =21a(6) =54a(7) =161a(8) =470a(9) =1347a(10) =4007a(11) =12199a(12) =37141a(13) =113802a(14) =352905a(15) =1101969a(16) =3455220a(17) =10891968a(18) =34515825a(19) =109814395a(20) =350616323a(21) =1123368287a(22) =3610647348a(23) =11637410625a(24) =37605280548a(25) =121812321775a(26) =395455199269