# Manuals/calci/REDHEFFER

**MATRIX("REDHEFFER",order)**

- is the size of the Redheffer matrix.

## Description

- This function gives the redheffer matrix of order 3.
- A Redheffer matrix is a square (0,1) -matrix with elements equal to 1 if j=1 or i/j (i divides j), and 0 otherwise. *For n=1, 2, ..., The first few Redheffer matrices are

- The determinant of the n×n Redheffer matrix is equal to the Mertens function M(n).

## Examples

- 1.MATRIX("redheffer") =1
- 2.MATRIX("redheffer",3)

1 | 1 | 1 |

1 | 1 | 0 |

1 | 0 | 1 |

- 3.MATRIX("redheffer",6)

1 | 1 | 1 | 1 | 1 | 1 |

1 | 1 | 0 | 1 | 0 | 1 |

1 | 0 | 1 | 0 | 0 | 1 |

1 | 0 | 0 | 1 | 0 | 0 |

1 | 0 | 0 | 0 | 1 | 0 |

1 | 0 | 0 | 0 | 0 | 1 |