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.

A130094 A051731 * an infinite lower triangular matrix with A007427 in the main diagonal.

Original entry on oeis.org

1, 1, -2, 1, 0, -2, 1, -2, 0, 1, 1, 0, 0, 0, -2, 1, -2, -2, 0, 0, 4, 1, 0, 0, 0, 0, 0, -2, 1, -2, 0, 1, 0, 0, 0, 0, 1, 0, -2, 0, 0, 0, 0, 0, 1, 1, -2, 0, 0, -2, 0, 0, 0, 0, 4
Offset: 1

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Author

Gary W. Adamson, May 06 2007

Keywords

Comments

Right border = A007427. Row sums = mu(n), A008683. Nonzero terms by rows are substituted for the factors of n such that row sums = mu(n). Example: for row 6 we map (1, -2, -2, 0, 4), sum = 1, since the factors of 6 are 1, 2, 3 and 6.

Examples

			First few rows of the triangle are:
  1;
  1, -2;
  1,  0, -2;
  1, -2,  0,  1;
  1,  0,  0,  0, -2;
  1, -2, -2,  0,  0,  4;
  1,  0,  0,  0,  0,  0, -2;
  1, -2,  0,  1,  0,  0,  0,  0;
  1,  0, -2,  0,  0,  0,  0,  0,  1;
  ...
		

Crossrefs

Formula

Inverse Möbius transform of a triangular matrix with A007427 in the main diagonal and the rest zeros.