# SageMath code for working with modular form 9248.2.a.bz


# Compute space of new eigenforms: 
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(9248, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0, 0, 0]))
N = Newforms(chi, 2, names="a")

# select newform: 
traces = [20,0,0,0,0,0,0,0,28,0,0,0,-8,0,16,0,0,0,40,0,-32,0,0,0,28,0,
0,0,0,0,0,0,0,0,32,0,0,0,0,0,0,0,40,0,0,0,32,0,36,0,0,0,-40,0,48,0,0,0,
8,0,0,0,0,0,0,0,72,0,-48,0,0,0,0,0,0,0,-48,0,0,0,36,0,24,0,0,0,96,0,64,
0,0,0,-32,0,0,0,0,0,0,0,-40,0,128,0,0,0,0,0,0,0,48,0,0,0,96,0,-72,0,0,
0,60,0,32,0,0,0,32,0,0,0,0,0,0,0,112,0,16,0,0,0,0,0,0,0,16]
f = next(g for g in N if [g.coefficient(i+1).trace() for i in range(145)] == traces)

# q-expansion: 
f.q_expansion() # note that sage often uses an isomorphic number field