# SageMath code for working with modular form 7200.2.m.e # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(7200, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([1, 1, 1, 1])) N = Newforms(chi, 2, names="a") # select newform: traces = [12,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,32,0,0,0,0,0,0,0,0,0,24] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(29)] == traces) # q-expansion: f.q_expansion() # note that sage often uses an isomorphic number field