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.

A368804 Irregular triangle read by rows: T(n,k) is the k-th balanced binary word of length 2*n, where words within a row are in lexicographical order (with leading zeros removed and interpreted as decimal numbers).

Original entry on oeis.org

1, 10, 11, 101, 110, 1001, 1010, 1100, 111, 1011, 1101, 1110, 10011, 10101, 10110, 11001, 11010, 11100, 100011, 100101, 100110, 101001, 101010, 101100, 110001, 110010, 110100, 111000, 1111, 10111, 11011, 11101, 11110, 100111, 101011, 101101, 101110, 110011, 110101, 110110
Offset: 1

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Author

Paolo Xausa, Jan 06 2024

Keywords

Comments

A balanced binary word is composed of the same number of zeros and ones.
This is triangle A362030 with terms converted to binary and interpreted as decimal numbers.

Examples

			Triangle begins (where terms in row n are padded with zeros on the left to form a 2*n word):
  [1] 01 10;
  [2] 0011 0101 0110 1001 1010 1100;
  [3] 000111 001011 001101 001110 010011 010101 010110 011001 011010 011100 ... ;
  ...
		

Crossrefs

Programs

  • Mathematica
    words[n_]:=Permutations[PadLeft[PadLeft[{},n,1],2n]];
    Array[Map[FromDigits,words[#]]&,4]