magma://Please install CHIMP (https://github.com/edgarcosta/CHIMP) if you want to run this code
chi := DirichletCharacter("2252.1125");
S:= CuspForms(chi, 3);
N := Newforms(S);
sage:from sage.modular.dirichlet import DirichletCharacter
H = DirichletGroup(2252, base_ring=CyclotomicField(2))
chi = DirichletCharacter(H, H._module([0, 1]))
N = Newforms(chi, 3, names="a")
This newform subspace can be constructed as the kernel of the linear operator
\( T_{3}^{38} - 2 T_{3}^{37} - 201 T_{3}^{36} + 389 T_{3}^{35} + 18318 T_{3}^{34} - 34246 T_{3}^{33} + \cdots - 175110945344480 \)
acting on \(S_{3}^{\mathrm{new}}(2252, [\chi])\).