G.f. satisfies: A(x) = x^3 - x + Series_Reversion(x - x*A(x)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =14a(6) =29a(7) =73a(8) =229a(9) =671a(10) =1840a(11) =5415a(12) =16983a(13) =52547a(14) =161420a(15) =511039a(16) =1655598a(17) =5372395a(18) =17527912a(19) =58076084a(20) =194676024a(21) =656160449a(22) =2227549164a(23) =7635624954a(24) =26380508479a(25) =91696805060a(26) =320866223000