# SageMath code for working with modular form 2523.1.h.c # Compute space of new eigenforms: from sage.modular.dirichlet import DirichletCharacter H = DirichletGroup(2523, base_ring=CyclotomicField(14)) chi = DirichletCharacter(H, H._module([7, 1])) 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