magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("112.65");
S:= CuspForms(chi, 12);
N := Newforms(S);
sage:from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(112, base_ring=CyclotomicField(6))
chi = DirichletCharacter(H, H._module([0, 0, 2]))
N = Newforms(chi, 12, names="a")
This newform subspace can be constructed as the kernel of the linear operator
\( T_{3}^{22} + 463 T_{3}^{21} + 1423202 T_{3}^{20} + 508514191 T_{3}^{19} + 1203980330744 T_{3}^{18} + \cdots + 14\!\cdots\!81 \)
acting on \(S_{12}^{\mathrm{new}}(112, [\chi])\).