# SageMath code for working with modular form 3240.1.z.h # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(3240, base_ring=CyclotomicField(6)) chi = DirichletCharacter(H, H._module([3, 3, 4, 3])) N = Newforms(chi, 1, names="a") # select newform: f = N[0] # Warning: the index may be different # q-expansion: f.q_expansion() # note that sage often uses an isomorphic number field