Cremona's table of elliptic curves

21 = 3 · 7

Field	Data	Notes
Atkin-Lehner	3- 7+	Signs for the Atkin-Lehner involutions
Conductor	21	Conductor
Count	6	Number of curves in isogeny class
Curves	21a1 21a2 21a3 21a4 21a5 21a6	Curves in isogeny class
deg	1	Modular degree for the optimal curve
Eigenvalues	-1 3- -2 7+  4 -2 -6  4	Hecke eigenvalues for primes less than 20
L	0.45111540538849	L(r)(E,1)/r!
r	0	Rank of the group of rational points
Twists	336e 1344a 63a 525b	Quadratic twists by: -4 8 -3 5

Hecke Eigenvalues for isogeny class 21a

a2	a3	a5	a7	a11	a13	a17	a19	a23	a29	a31	a37	a41	a43	a47	a53	a59	a61	a67	a71	a73	a79	a83	a89	a97
-1	-	-2	+	4	-2	-6	4	0	-2	0	6	2	-4	0	6	12	-2	4	0	-6	-16	-12	-14	18

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Quadratic twists for isogeny class 21a

-4	8	-3	5	-7	-11	13	17	-19	-23	29	-31	37	41	-43	-47	53	-59	61	-67	-71	73
336e	1344a	63a	525b	147a	2541l	3549c	6069b	7581b	11109i	17661a	20181d	28749e	35301e	38829f	46389k	58989a	73101b	78141h	94269f	105861g	111909i

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Data from Elliptic Curve Data by J. E. Cremona.
Design inspired by The Modular Forms Explorer by William Stein.

Part of Computational Number Theory
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