# SageMath code for working with modular form 24843.2.a.bv


# Compute space of new eigenforms: 
from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(24843, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0, 0, 0]))
N = Newforms(chi, 2, names="a")

# select newform: 
traces = [3,0,-3,0,6,0,0,3,3,3,-6,0,0,0,-6,-6,-6,0,9,-3,0,-3,3,-3,3,0,
-3,0,9,-3,9,-9,6,-6,0,0,-12,6,0,3,6,0,9,-15,6,21,3,6,0,6,6,0,3,0,0,0,-9,
-30,15,3,15,-9,0,-3,0,3,-9,-21,-3,0,12,3,30,-21,-3,-6,0,0,-21,0,3,0,24,
0,3,-15,-9,-3,-9,3,0,6,-9,-15,30,9,3,0,-6,-15]
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