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

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =12a(5) =60a(6) =130a(7) =420a(8) =8400a(9) =101080a(10) =781200a(11) =4435200a(12) =37714600a(13) =607807200a(14) =8660652000a(15) =94007313400a(16) =914497584000