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.

A282063 A(n, k) = k-th Wilson prime p of order n with p >= n and k running over the positive integers. Square array read by antidiagonals.

Original entry on oeis.org

5, 13, 2, 563, 3, 7
Offset: 1

Views

Author

Felix Fröhlich, Feb 05 2017

Keywords

Comments

A Wilson prime of order n is a prime p such that (n-1)!*(p-n)!-(-1)^n == 0 (modulo p^2).

Examples

			Array A(n, k) starts:
      5,   13,  563
      2,    3,   11,  107, 4931
      7
  10429
      5,    7,   47
     11
		

Crossrefs

Cf. A007540 (row 1), A079853 (row 2), A152413 (row 17), A128666 (column 1).

Programs

  • PARI
    is_wilson(n, order) = Mod((order-1)!*(n-order)!-(-1)^order, n^2)==0
    table(rows, cols) = for(x=1, rows, my(i=0); forprime(p=x, , if(is_wilson(p, x), print1(p, ", "); i++; if(i==cols, print(""); break))))
    table(4, 3) \\ print initial 4 rows and 3 columns of table