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.

A143425 Triangle read by rows A051731 * A130123, 1<=k<=n.

Original entry on oeis.org

1, 1, 2, 1, 0, 4, 1, 2, 0, 8, 1, 0, 0, 0, 16, 1, 2, 4, 0, 0, 32, 1, 0, 0, 0, 0, 0, 64, 1, 2, 0, 8, 0, 0, 0, 128, 1, 0, 4, 0, 0, 0, 0, 0, 256, 1, 2, 0, 0, 16, 0, 0, 0, 0, 512, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1024, 1, 2, 4, 8, 0, 32, 0, 0, 0, 0, 0, 2048
Offset: 1

Views

Author

Gary W. Adamson, Aug 14 2008

Keywords

Comments

Row sums = A034729: (1, 3, 5, 11, 17, ...).

Examples

			First few rows of the triangle are:
  1;
  1, 2;
  1, 0, 4;
  1, 2, 0, 8;
  1, 0, 0, 0, 16;
  1, 2, 4, 0,  0, 32;
  ...
		

Crossrefs

Programs

  • PARI
    tabl(nn) = {ma = matrix(nn, nn, n, k, !(n%k)); mb = matrix(nn, nn, n, k, n--; k--; if (n==k, 2^n, 0)); m = ma*mb; for (n=1, nn, for (k=1, n, print1(m[n, k], ", ");); print(););} \\ Michel Marcus, Jun 30 2017

Formula

Triangle read by rows A051731 * A130123, 1<=k<=n, where A130123 = an infinite lower triangular matrix with (1, 2, 4, 8, ...) in the main diagonal and the rest zeros. A051731 = the inverse Mobius transform.

Extensions

Typo in data corrected by Michel Marcus, Jun 30 2017