# SageMath code for working with modular form 700.2.be.e # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(700, base_ring=CyclotomicField(12)) chi = DirichletCharacter(H, H._module([6, 3, 4])) N = Newforms(chi, 2, names="a") # select newform: traces = [72,-2,0] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(3)] == traces) # q-expansion: f.q_expansion() # note that sage often uses an isomorphic number field