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

Terms

a(0) =0a(1) =1a(2) =2a(3) =12a(4) =84a(5) =660a(6) =5548a(7) =48836a(8) =444412a(9) =4147220a(10) =39471436a(11) =381671204a(12) =3738957148a(13) =37028943860a(14) =370123733932