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.

A191607 Table of the difference of numerator and denominator of Farey sequences, read by rows.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 2, 1, 1, 0, 1, 3, 2, 1, 1, 1, 0, 1, 4, 3, 2, 3, 1, 2, 1, 1, 1, 0, 1, 5, 4, 3, 2, 3, 1, 2, 1, 1, 1, 1, 0, 1, 6, 5, 4, 3, 5, 2, 3, 4, 1, 3, 2, 1, 2, 1, 1, 1, 1, 0, 1, 7, 6, 5, 4, 3, 5, 2, 5, 3, 4, 1, 3, 2, 3, 1, 2, 1, 1, 1, 1, 1, 0, 1, 8, 7, 6, 5, 4, 7, 3, 5, 2, 5, 3, 4, 5, 1, 4, 3, 2, 3, 1, 2, 1, 2, 1, 1, 1, 1, 1, 0
Offset: 1

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Author

Robert G. Wilson v, Jun 11 2011

Keywords

Comments

For n>=1, the n-th row begins with 1, n-1 and ends with 1, 0.
1, 0
1, 1, 0
1, 2, 1, 1, 0
1, 3, 2, 1, 1, 1, 0
1, 4, 3, 2, 3, 1, 2, 1, 1, 1, 0
etc.
Row n has A005728(n) terms. - Michel Marcus, Jun 27 2014

Crossrefs

Cf. A133404.

Programs

  • Mathematica
    Farey[n_] := Union[ Flatten[ Join[{0}, Table[a/b, {b, n}, {a, b}]]]]; Table[ -Numerator@ Farey@ n + Denominator@ Farey@ n, {n, 9}] // Flatten