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.

A308765 Irregular triangle T(n,k) read by rows with 1 <= k <= A091887 even indices 2i such that n-th irregular prime p (A000928) divides the numerator of the Bernoulli numbers B_{2i} (A000367) with 0 <= 2i <= p-3.

Original entry on oeis.org

32, 44, 58, 68, 24, 22, 130, 62, 110, 84, 164, 100, 84, 20, 156, 88, 292, 280, 186, 300, 100, 174, 200, 382, 126, 240, 366, 196, 130, 94, 194, 292, 336, 338, 400, 86, 270, 486, 222, 52, 90, 92, 22, 592, 522, 20, 174, 338, 428, 80, 226, 236, 242, 554, 48, 224, 408, 502, 628, 32, 12, 200, 378, 290, 514, 260, 732, 220, 330, 628, 544, 744, 102, 66, 868, 162, 418, 520, 820, 156, 166
Offset: 1

Views

Author

Martin Renner, Jun 23 2019

Keywords

Comments

First index T(n,1) in row n is A035112(n).

Examples

			Triangle starts with
n = 1 => p = 37 divides the numerator of B_{32} = -7709321041217;
n = 2 => p = 59: B_{44};
n = 3 => p = 67: B_{58};
n = 4 => p = 101: B_{68};
n = 5 => p = 103: B_{24};
n = 6 => p = 131: B_{22};
n = 7 => p = 149: B_{130};
n = 8 => p = 157: B_{62}, B_{110};
n = 9 => p = 233: B_{84};
etc.
		

Crossrefs

Programs

  • Maple
    T:=[]:
    for j from 2 to 168 do
      p:=ithprime(j);
      B:=[]:
      for i from 1 to (p-3)/2 do
        if type(numer(bernoulli(2*i))/p,integer) then B:=[op(B),2*i]: fi:
      od:
      T:=[op(T),op(B)];
    od:
    op(T);