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.

A144735 Square of triangle A054533 (matrix square), read by rows.

Original entry on oeis.org

1, -2, 1, -2, -3, 4, 2, -6, 0, 4, -3, -2, -6, -6, 16, 5, 0, -9, -5, 6, 4, -5, -2, -5, -6, -11, -8, 36, 0, 8, 0, -24, 0, 0, 0, 16, 0, 6, -18, 3, -3, -24, 0, 0, 36, 7, 0, 8, 2, -34, -10, 10, -8, 10, 16
Offset: 1

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Author

Gary W. Adamson, Sep 20 2008

Keywords

Comments

Row sums = A008683, mu(n).
Right border = squares of phi(n).

Examples

			First few rows of the triangle are as follows:
   1;
  -2,  1;
  -2, -3,   4;
   2, -6,   0,   4;
  -3, -2,  -6,  -6,  16;
   5,  0,  -9,  -5,   6,   4;
  -5, -2,  -5,  -6, -11,  -8, 36;
   0,  8,   0, -24,   0,   0,  0, 16;
   0,  6, -18,   3,  -3, -24,  0,  0, 36;
   7,  0,   8,   2, -34, -10, 10, -8, 10, 16;
   ...
		

Crossrefs

Formula

A054533^2, as an infinite lower triangular matrix.
T(n, k) = Sum_{s = k..n} R(n, s) * R(s, k) for n >= 1 and 1 <= k <= n, where R(n, s) = A054533(n, s) = Sum_{d | gcd(n,s)} d * mu(n/d). - Petros Hadjicostas, Jul 29 2019