Theta series of D_15 lattice.

Terms

a(0) =1a(1) =420a(2) =21870a(3) =331240a(4) =2128260a(5) =8972712a(6) =29822520a(7) =80027280a(8) =193511790a(9) =409172940a(10) =825736296a(11) =1509537960a(12) =2698852520a(13) =4472616120a(14) =7347537600a(15) =11335886864a(16) =17520853380a(17) =25553816400a(18) =37658603350a(19) =52706867640a(20) =74655559272a(21) =100969845200a(22) =138840872040a(23) =182317633680