# SageMath code for working with modular form 6050.2.a.l # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(6050, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 0])) N = Newforms(chi, 2, names="a") # select newform: traces = [1,-1,1,1,0,-1,3,-1,-2,0,0,1,0,-3,0,1,-8,2,8] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(19)] == traces) # q-expansion: f.q_expansion() # note that sage often uses an isomorphic number field