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

Terms

a(0) =1a(1) =0a(2) =2a(3) =6a(4) =32a(5) =190a(6) =1332a(7) =10654a(8) =95888a(9) =958878a(10) =10547660a(11) =126571918a(12) =1645434936a(13) =23036089102a(14) =345541336532