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.

A379881 Prime numbers of the form 8*x^2 + 27*y^2 where x and y are positive integers.

Original entry on oeis.org

59, 227, 251, 419, 443, 683, 827, 1187, 1451, 1523, 1811, 2027, 2243, 2339, 2579, 2699, 3299, 3371, 3467, 3539, 3659, 3779, 4211, 4259, 4523, 4547, 4691, 5387, 5531, 5651, 6131, 6203, 6299, 6323, 6947, 6971, 7043, 7187, 7451, 7499, 7643, 8123, 8219, 8363, 8387, 8867, 8963, 9011, 9371, 9491, 9539, 9851, 9923
Offset: 1

Views

Author

Steven Lu, Feb 16 2025

Keywords

Comments

All terms are congruent to 11 modulo 24.

Examples

			59 = 8 * 2^2 + 27 * 1^2
227 = 8 * 5^2 + 27 * 1^2
251 = 8 * 1^2 + 27 * 3^2
		

Crossrefs

Intersection of A107161 and A002145.

Programs

  • Mathematica
    With[{limit = 10000}, Sort[DeleteDuplicates[Select[Flatten[Table[8 x^2 + 27 y^2, {x, Floor[Sqrt[limit/8]]}, {y, Floor[Sqrt[limit/27]]}]], PrimeQ[#] && # < limit &]]]]