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.

A083558 p(p^2-p+1) as p runs through the primes.

Original entry on oeis.org

6, 21, 105, 301, 1221, 2041, 4641, 6517, 11661, 23577, 28861, 49321, 67281, 77701, 101661, 146121, 201957, 223321, 296341, 352941, 383761, 486877, 564981, 697137, 903361, 1020201, 1082221, 1213701, 1283257, 1430241, 2032381, 2231061, 2552721, 2666437
Offset: 1

Views

Author

N. J. A. Sloane, Jun 15 2003

Keywords

Comments

Warning: not all quizzes permit the use of the OEIS!
Discard (from the list of integers) numbers that have exactly 1 factor of prime(n) in their prime factorization. Of those remaining, the proportion that have exactly 2 factors of prime(n) is (prime(n)-1)/a(n). - Peter Munn, Nov 27 2020

Crossrefs

Programs

  • Magma
    [p*(p^2-p+1): p in PrimesUpTo(150)]; // Vincenzo Librandi, Jan 10 2017
  • Mathematica
    Table[p(p^2-p+1),{p,Prime[Range[40]]}] (* Harvey P. Dale, Jan 09 2017 *)

Formula

a(n) = A000040(n) * A119959(n). - Peter Munn, Nov 29 2020