Expansion of e.g.f. theta_3^(7/2).

Terms

a(0) =1a(1) =7a(2) =35a(3) =105a(4) =273a(5) =4095a(6) =38115a(7) =86625a(8) =540225a(9) =22444695a(10) =215417475a(11) =1819488825a(12) =18942548625a(13) =273922023375