# SageMath code for working with modular form 45760.2.a.fh # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(45760, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 0, 0, 0, 0])) B = ModularForms(chi, 1).cuspidal_submodule().basis() N = [B[i] for i in range(len(B))] # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(45760, base_ring=CyclotomicField(2)) chi = DirichletCharacter(H, H._module([0, 0, 0, 0, 0])) N = Newforms(chi, 2, names="a") # select newform: traces = [7,0,3,0,7,0,5,0,14,0,7,0,7,0,3,0,13,0,4,0,-2,0,1,0,7,0,12,0, 6,0,10,0,3,0,5,0,-3,0,3,0,32,0,11,0,14,0,-3,0,-2,0,-18,0,-9,0,7,0,-3,0, 2,0,-10,0,6,0,7,0,11,0,4,0,10,0,31,0,3,0,5,0,-6,0,19,0,-1,0,13,0,-16,0, 6,0,5,0,-4,0,4,0,33,0,14,0] f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(None)] == traces) # q-expansion: f.q_expansion() # note that sage often uses an isomorphic number field