Theta series of D_20 lattice.

Terms

a(0) =1a(1) =760a(2) =77560a(3) =2508000a(4) =34729720a(5) =259114704a(6) =1327461600a(7) =5341699520a(8) =17701924600a(9) =51294999960a(10) =131880275664a(11) =312126610080a(12) =680432137440