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.

A184478 Lower s-Wythoff sequence, where s(n) = 3n + 1. Complement of A184479.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, 20, 21, 23, 24, 25, 27, 28, 29, 31, 32, 33, 34, 36, 37, 38, 40, 41, 42, 44, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, 59, 60, 62, 63, 64, 66, 67, 68, 70, 71, 72, 74, 75, 76, 77, 79, 80, 81, 83, 84, 85, 87, 88, 89, 90, 92, 93, 94, 96, 97, 98, 100, 101, 102, 103, 105, 106, 107, 109, 110, 111, 113, 114, 115, 117, 118, 119, 120, 122, 123, 124, 126, 127, 128, 130, 131, 132, 133, 135, 136, 137, 139, 140, 141, 143, 144, 145, 146, 148, 149, 150, 152, 153, 154, 156
Offset: 1

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Author

Clark Kimberling, Jan 15 2011

Keywords

Comments

See A184117 for the definition of lower and upper s-Wythoff sequences.
The sequence is defined by a(1) = 1 and for n > 1, a(n) is the smallest positive integer not in {a(k), a(k) + s(k); k < n}. - M. F. Hasler, Jan 07 2019

Crossrefs

Programs

  • Magma
    [(Floor(n*(-1+Sqrt(13))/2))+1: n in [0..120]]; // Vincenzo Librandi, Jan 08 2019
  • Maple
    a:=n->floor(n*(-1+sqrt(13))/2+1): seq(a(n),n=0..120); # Muniru A Asiru, Jan 08 2019
  • Mathematica
    k=3; r=-1; d=Sqrt[4+k^2];
    a[n_]:=Floor[(1/2)(d+2-k)(n+r/(d+2))];
    b[n_]:=Floor[(1/2)(d+2+k)(n-r/(d+2))];
    Table[a[n],{n,120}]
    Table[b[n],{n,120}]
    Table[(Floor[n (-1 + Sqrt[13]) / 2]) + 1, {n, 0, 120}] (* Vincenzo Librandi, Jan 08 2019 *)
  • PARI
    A184478_upto(N, s(n)=3*n+1, a=[1], U=a)={while(a[#a]1&&U[2]==U[1]+1, U=U[^1]); a=concat(a, U[1]+1)); a} \\ M. F. Hasler, Jan 07 2019
    

Formula

a(n) = A184479(n) - s(n). - M. F. Hasler, Jan 07 2019