Atlas › Modular forms › Weight 2 › Level 318 › 318.2.a › 318.2.a.c

Newform orbit 318.2.a.c

$q$ -expansion

$q - q^{2} + q^{3} + q^{4} - q^{6} + 5q^{7} - q^{8} + q^{9} - 3q^{11} + q^{12} - 4q^{13} - 5q^{14} + q^{16} + 6q^{17} - q^{18} + 5q^{19} + 5q^{21} + 3q^{22} - 3q^{23} - q^{24} + O(q^{25})$

Coefficient field

The coefficients $a_n$ generate $\mathbb{Q}$ . The eigenvalue of $T = T_{5} + 3T_{7}$ is a root of

$x - 15$

Atkin–Lehner signs

$p$	$w_p$
2	$+1$
3	$-1$
53	$+1$

For $p \parallel N$ every form in the orbit has $a_p = -p^{k/2-1} w_p$ . The Fricke sign is $w_N = -1$ , so the sign of the functional equation is $(-1)^{k/2} w_N = +1$ : each L-function in the orbit has even analytic rank.

Elliptic curve

By modularity this newform is the one attached to the isogeny class 318.c (Cremona's 318b). Its optimal curve 318b1 is

$y^2 + xy + y = x^3 - 61x + 176$

of rank 0 with torsion of order 3. Its $a_p$ , computed by Sagebrush's point-counting engine, equal the newform's for every prime $p < 1000$ .

Traces of Hecke eigenvalues

$p$	2	3	5	7	11	13	17	19	23	29	31	37	41	43	47	53	59	61	67	71	73	79	83	89	97
$\operatorname{tr} a_p$	−1	1	0	5	−3	−4	6	5	−3	3	8	−4	−3	−4	6	−1	−12	−1	−13	−15	2	−16	0	0	5

$\operatorname{tr} a_n$ for every $n \le 1000$ is in the JSON.

Sato–Tate

The normalized $a_p / 2p^{1/2}$ for the primes $p < 1000$ not dividing 318, against the semicircle $\tfrac{2}{\pi}\sqrt{1 - x^2}$ :

Provenance

Stored in the atlas: computed by Sagebrush's modular symbols engine in 0.331 s (one thread) and proven: the dimensions are certified, and the characteristic polynomial of $T$ over $\mathbb{Z}$ is reconstructed by CRT past a rigorous coefficient bound. The label, dimension and $\operatorname{tr} a_p$ for every $p < 1000$ equal LMFDB's.

The engine's checks

dim M^+ at levels [1, 2, 3, 6, 53, 106, 159, 318]: [0, 1, 1, 3, 5, 15, 20, 58] (certified at ell = 2147483053)
T = [(5, 1), (7, 3)]; h of degree 9 = 1 x 9 (phi(ord eps) x dim S_k^new); 2 primes, 0 rejected

Open in the notebook · JSON · stored data

Recompute it yourself

In Sage mode at sagebrush.space (or npx sagebrush --sage):

newform_orbits(318, 2)[2]   # 318.2.a.c

With the Rust engine (source), in engine/:

cargo run --release -p sagebrush-web --example atlas -- 318:2 1000