Expansion of e.g.f. exp(Sum_{k>=0} x^(3*k + 1) / (3*k + 1)!).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =6a(6) =16a(7) =37a(8) =114a(9) =478a(10) =1907a(11) =6777a(12) =28414a(13) =148579a(14) =758916a(15) =3580189a(16) =18981485a(17) =117883917a(18) =720627553a(19) =4193077474a(20) =26795418840a(21) =191751387094