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.

A338971 Linear representation of the complete labeled binary trees of all integer heights, where the nodes at level i, 0 <= i <= n, of a binary tree with height n are labeled with the number n-i.

Original entry on oeis.org

0, 1, 0, 0, 2, 1, 1, 0, 0, 0, 0, 3, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Marc van Dongen, Dec 18 2020

Keywords

Examples

			First few terms where each line represents a complete binary tree:
  n=0:  0
  n=1:  1 0 0
  n=2:  2 1 1 0 0 0 0
  n=3:  3 2 2 1 1 1 1 0 0 0 0 0 0 0 0
  n=4:  4 3 3 ...
Using this representation, the first row r(0) is given by [0]; row(n+1) is given by adding 1 to each member of r(n) and appending 2^(n+1) 0's: r(0) = [0], r(n+1) = [ i + 1 | i <- r(n) ] ++ [ 0 | i <- [1..2^(n+1)] ].
		

Crossrefs

Cf. A290255, A126646 (row lengths).

Programs

  • Haskell
    concat [ tree n | n <- [0..] ]
      where tree 0 = [0]
            tree n = [ i+1 | i <- tree (n-1) ] ++ [ 0 | i <- [1..2^n] ]