# SageMath code for working with modular form 45760.2.a.k


# 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 = [1,0,-2,0,1,0,-2,0,1,0,-1,0,1,0,-2,0,3,0,5,0,4,0,2,0,1,0,4,0,
-2,0,6,0,2,0,-2,0,3,0,-2,0,-9,0,-9,0,1,0,-3,0,-3,0,-6,0,4,0,-1,0,-10,0,
8,0,-8,0,-2,0,1,0,11,0,-4,0,8,0,-2,0,-2,0,2,0,-10,0,-11,0,18,0,3,0,4,0,
-8,0,-2,0,-12,0,5,0,-9,0,-1,0]
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