sage:from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(936, base_ring=CyclotomicField(6))
chi = DirichletCharacter(H, H._module([0, 0, 4, 3]))
N = Newforms(chi, 2, names="a")
magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("936.25");
S:= CuspForms(chi, 2);
N := Newforms(S);
This newform subspace can be constructed as the kernel of the linear operator
\( T_{5}^{80} - 122 T_{5}^{78} + 8157 T_{5}^{76} - 376440 T_{5}^{74} + 13245432 T_{5}^{72} + \cdots + 4746193387776 \)
acting on \(S_{2}^{\mathrm{new}}(936, [\chi])\).