Trace form
The 23 newforms in this orbit are conjugate over Q; the sum of their q-expansions is
23qβ9q2β7q3+15q4β11q5β10q6β6q7β24q8+10q9β50q11β6q12β9q13β12q14β20q15+7q16β11q17β14q18β27q19β20q20β19q21+16q22β23q23β18q24+O(q25)
Coefficient field
The coefficients anβ generate a number field of degree 23. It is generated by the eigenvalue Ξ± of T=T2β+T3β, whose minimal polynomial is
x23+16x22+68x21β176x20β1922x19β1702x18+17890x17+36839x16β73752x15β232844x14+120871x13+702344x12+20875x11β1096428x10β282538x9+863795x8+276425x7β300407x6β81301x5+31666x4+8628x3β538x2β198xβ9
AtkinβLehner signs
For pβ₯N every form in the orbit has apβ=βpk/2β1wpβ. The Fricke sign is wNβ=+1, so the sign of the functional equation is (β1)k/2wNβ=β1: each L-function in the orbit has odd analytic rank.
Traces of Hecke eigenvalues
tranβ for every nβ€1000 is in the JSON.
Provenance
Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.223 s (one thread) and proven: the dimensions are certified, and the characteristic polynomial of T over Z is reconstructed by CRT past a rigorous coefficient bound.
The label, dimension and trapβ for every p<1000 equal LMFDB's.
The engine's checks
dim M^+ at levels [1, 661]: [0, 55] (certified at ell = 2147482921)T = [(2, 1), (3, 1)]; h of degree 54 = 1 x 54 (phi(ord eps) x dim S_k^new); 6 primes, 0 rejected
Recompute it yourself
In Sage mode at sagebrush.space (or npx sagebrush --sage):
newform_orbits(661, 2)[1] # 661.2.a.b
With the Rust engine (source), in engine/:
cargo run --release -p sagebrush-web --example atlas -- 661:2 1000