Expansion of e.g.f. 1/((1-2*x^2)*(1-x)).

Terms

a(0) =1a(1) =1a(2) =6a(3) =18a(4) =168a(5) =840a(6) =10800a(7) =75600a(8) =1249920a(9) =11249280a(10) =228614400a(11) =2514758400a(12) =60833203200a(13) =790831641600