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.

Showing 1-2 of 2 results.

A023679 Discriminants of complex cubic fields (negated).

Original entry on oeis.org

23, 31, 44, 59, 76, 83, 87, 104, 107, 108, 116, 135, 139, 140, 152, 172, 175, 199, 200, 204, 211, 212, 216, 231, 239, 243, 244, 247, 255, 268, 283, 300, 307, 324, 327, 331, 335, 339, 351, 356, 364, 367, 379, 411, 419, 424, 431, 436, 439, 440, 451, 459, 460, 472, 484, 491, 492, 499, 503
Offset: 1

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Examples

			The field Q[x]/(x^3 - x^2 + 1) is the complex cubic field with the smallest absolute discriminant of 23. - _Robin Visser_, Mar 27 2025
		

References

  • M. Pohst and H. Zassenhaus, Algorithmic Algebraic Number Theory, Cambridge Univ. Press, 1989, p. 437.

Crossrefs

Extensions

More terms added by Robin Visser, Mar 27 2025, taken from the database of John Jones and David Roberts.

A278790 Number of real cubic fields with discriminant <= 10^n.

Original entry on oeis.org

0, 2, 27, 382, 4804, 54600, 592922, 6248290, 64659361, 661448081, 6715824025
Offset: 1

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Comments

Belabas invented an algorithm to identify all cubic fields with a discriminant bounded by X in essentially linear time, and computed the above values up to a(11).
The number of real cubic fields with discriminant <= X is asymptotic to X/(12*zeta(3)) = (0.069325...)*X. The second order term was conjectured by Roberts to be a known constant times X^{5/6}, and this was subsequently proved by Bhargava et al.

References

  • Henri Cohen, Advanced Topics in Computational Number Theory, Springer, 2000, p. 426 (and Chapter 8 more generally).

Crossrefs

Showing 1-2 of 2 results.