magma:// Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("432.145");
S:= CuspForms(chi, 8);
N := Newforms(S);
sage:from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(432, base_ring=CyclotomicField(6))
chi = DirichletCharacter(H, H._module([0, 0, 2]))
N = Newforms(chi, 8, names="a")
This newform subspace can be constructed as the kernel of the linear operator
\( T_{5}^{22} - 125 T_{5}^{21} + 492084 T_{5}^{20} - 57952559 T_{5}^{19} + 154919763673 T_{5}^{18} + \cdots + 17\!\cdots\!00 \)
acting on \(S_{8}^{\mathrm{new}}(432, [\chi])\).