Theta series of 15-dimensional unimodular lattice A15+.

Terms

a(0) =1a(1) =0a(2) =240a(3) =3640a(4) =23790a(5) =99456a(6) =323680a(7) =895680a(8) =2139780a(9) =4528640a(10) =8971872a(11) =16946280a(12) =29822520a(13) =49365120a(14) =80003520a(15) =127221568a(16) =193388910a(17) =282616320a(18) =409634640a(19) =590913960a(20) =825575016a(21) =1115613440