Expansion of e.g.f. exp(x / (1 - x^3/6)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =5a(5) =21a(6) =61a(7) =281a(8) =1961a(9) =10585a(10) =59641a(11) =509521a(12) =4086061a(13) =29792621a(14) =288051765a(15) =2997900361a(16) =27857436881a(17) =302238265841