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.

A182761 Beatty sequence for (7 - sqrt(5))/2.

Original entry on oeis.org

2, 4, 7, 9, 11, 14, 16, 19, 21, 23, 26, 28, 30, 33, 35, 38, 40, 42, 45, 47, 50, 52, 54, 57, 59, 61, 64, 66, 69, 71, 73, 76, 78, 80, 83, 85, 88, 90, 92, 95, 97, 100, 102, 104, 107, 109, 111, 114, 116, 119, 121, 123, 126, 128, 131, 133
Offset: 1

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Author

Clark Kimberling, Nov 28 2010

Keywords

Comments

See the first comment at A182760; its complement, A182761, gives the positions of the numbers k*sqrt(5) when these numbers and the numbers j*u, where u = golden ratio, are jointly ranked.

Crossrefs

Cf. A182760.

Programs

  • Magma
    [Floor(n*(7-5^(1/2))/2): n in [1..80]]; // Vincenzo Librandi, Oct 25 2011
    
  • Mathematica
    Table[Floor[n*(7-Sqrt[5])/2], {n,1,80}] (* G. C. Greubel, Jul 08 2018 *)
  • PARI
    for(n=1,80, print1(floor(n*(7-sqrt(5))/2), ", ")) \\ G. C. Greubel, Jul 08 2018

Formula

a(n) = floor(n*(7 - sqrt(5))/2).

Extensions

Typo in formula corrected by Vincenzo Librandi, Oct 25 2011