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.

A353296 Pairs (i,j) of positive integers with at least one common 1-bit sorted first by i+j then by i.

Original entry on oeis.org

1, 1, 1, 3, 2, 2, 3, 1, 2, 3, 3, 2, 1, 5, 3, 3, 5, 1, 1, 7, 2, 6, 3, 5, 4, 4, 5, 3, 6, 2, 7, 1, 2, 7, 3, 6, 4, 5, 5, 4, 6, 3, 7, 2, 1, 9, 3, 7, 4, 6, 5, 5, 6, 4, 7, 3, 9, 1, 4, 7, 5, 6, 6, 5, 7, 4, 1, 11, 2, 10, 3, 9, 5, 7, 6, 6, 7, 5, 9, 3, 10, 2, 11, 1
Offset: 1

Views

Author

Rémy Sigrist and N. J. A. Sloane, Apr 09 2022

Keywords

Comments

Pairs (i,j) with AND(i,j) <> 0.
See A352909 for the other pairs.
There are A048967(n) pairs (i,j) with n = i+j.

Examples

			The first pairs are:
    [1, 1],
    [1, 3], [2, 2], [3, 1],
    [2, 3], [3, 2],
    [1, 5], [3, 3], [5, 1],
    [1, 7], [2, 6], [3, 5], [4, 4], [5, 3], [6, 2], [7, 1],
    [2, 7], [3, 6], [4, 5], [5, 4], [6, 3], [7, 2],
    [1, 9], [3, 7], [4, 6], [5, 5], [6, 4], [7, 3], [9, 1],
    ...
		

Crossrefs

Cf. A004198, A048967, A352909, A353297 (i values), A353298 (j values).

Programs

  • Mathematica
    A353296row[ij_] := Select[Array[{#, ij-#} &, ij], BitAnd @@ # > 0 &];
    Array[A353296row, 15] (* Paolo Xausa, Feb 24 2024 *)
  • PARI
    for (ij=1, 12, for (i=1, ij, j=ij-i; if (bitand(i,j), print1(i", "j", "))))