Theta series of 20-dimensional lattice L_20 with group 2.M_22.2.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =6160a(5) =27104a(6) =157080a(7) =633600a(8) =2152920a(9) =6049120a(10) =15601432a(11) =37243360a(12) =81265800a(13) =166554080a(14) =325036800a(15) =603357216a(16) =1082004000a(17) =1863350720a(18) =3121660080a(19) =5069606080a(20) =8058310568a(21) =12471782400a(22) =19002534320a(23) =28292374880a(24) =41585775000a(25) =59922289504a(26) =85450069320