# Properties

 Label 256.c Number of curves $2$ Conductor $256$ CM $$\Q(\sqrt{-1})$$ Rank $0$ Graph

# Related objects

Show commands for: SageMath
sage: E = EllipticCurve("c1")

sage: E.isogeny_class()

## Elliptic curves in class 256.c

sage: E.isogeny_class().curves

LMFDB label Cremona label Weierstrass coefficients Torsion structure Modular degree Optimality CM discriminant
256.c1 256c2 [0, 0, 0, -8, 0] [2] 16   -4
256.c2 256c1 [0, 0, 0, 2, 0] [2] 8 $$\Gamma_0(N)$$-optimal -4

## Rank

sage: E.rank()

The elliptic curves in class 256.c have rank $$0$$.

## Complex multiplication

Each elliptic curve in class 256.c has complex multiplication by an order in the imaginary quadratic field $$\Q(\sqrt{-1})$$.

## Modular form256.2.a.c

sage: E.q_eigenform(10)

$$q + 4q^{5} - 3q^{9} + 4q^{13} - 2q^{17} + O(q^{20})$$

## Isogeny matrix

sage: E.isogeny_class().matrix()

The $$i,j$$ entry is the smallest degree of a cyclic isogeny between the $$i$$-th and $$j$$-th curve in the isogeny class, in the LMFDB numbering.

$$\left(\begin{array}{rr} 1 & 2 \\ 2 & 1 \end{array}\right)$$

## Isogeny graph

sage: E.isogeny_graph().plot(edge_labels=True)

The vertices are labelled with LMFDB labels.