cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A385881 Algebraic rank of elliptic curve y^2 = x^3 - n*x - n.

Original entry on oeis.org

0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 2, 1, 1, 0, 0, 0, 0, 0, 1, 2, 1, 1, 2, 2, 0, 2, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 2, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 2, 0, 1, 0, 1, 1, 1, 0, 1, 2, 1
Offset: 1

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Author

Shreyansh Jaiswal, Aug 20 2025

Keywords

Comments

Terms from n = 43 onward are the analytic ranks (see PARI code) of the corresponding elliptic curves. By the BSD conjecture, these are expected to equal the algebraic ranks. Thus, the validity of these terms is conditional on BSD.

Examples

			a(1) = 0 because y^2 = x^3 - x - 1 has rank 0.
		

Crossrefs

Programs

  • PARI
    a(n) = ellanalyticrank( ellinit([0, 0, 0, -n, -n]) )[1]; \\ Michel Marcus, Aug 20 2025
  • SageMath
    for k in range(1, 43):
        E = EllipticCurve([-k, -k])
        print(E.rank(), end=", ")
    

Extensions

More terms from Michel Marcus, Aug 20 2025