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

Terms

a(0) =0a(1) =1a(2) =5a(3) =16a(4) =59a(5) =251a(6) =890a(7) =3270a(8) =12269a(9) =45793a(10) =167360a(11) =596036a(12) =2070755a(13) =7041087a(14) =23517590a(15) =77417074a(16) =251879897a(17) =811815485a(18) =2596707692a(19) =8255064768a(20) =26112370895a(21) =82260512731a(22) =258263585090a(23) =808543518254