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.

A337909 Distinct terms of A080079 in the order in which they appear.

Original entry on oeis.org

1, 2, 4, 3, 8, 7, 6, 5, 16, 15, 14, 13, 12, 11, 10, 9, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 128
Offset: 1

Views

Author

Keywords

Comments

This sequence is a permutation of the positive integers.
The cardinality of {2^k, ..., (2^k - 0^k)/2 + 1} is A011782(k).

Examples

			(2^0, ..., (2^0 - 0^0)/2 + 1) = (1),
(2^1, ..., (2^1 - 0^1)/2 + 1) = (2),
(2^2, ..., (2^2 - 0^2)/2 + 1) = (4, 3),
(2^3, ..., (2^3 - 0^3)/2 + 1) = (8, 7, 6, 5)...
		

Crossrefs

Programs

  • Mathematica
    {1}~Join~Array[3*2^(IntegerLength[# - 1, 2] - 1) - # + 1 &, 64, 2] (* Michael De Vlieger, Oct 05 2020 *)
  • PARI
    a(n) = if(n--, 3<Kevin Ryde, Sep 29 2020

Formula

a(1) = 1 and a(n) = A080079(n - 1 + 2^floor(log_2(n - 1))) if n > 1.
a(n) = A080079(A004761(n+1)).
From Kevin Ryde, Sep 29 2020: (Start)
a(n) = 3*A053644(n-1) - (n-1), if n > 1.
a(n) = A054429(n-1) + 1, if n > 1.
a(n) = A280510(n) - n + 1, if n > 1. (End)