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.

A030718 The second list after the following procedure: starting with a list [1] and an empty list, repeatedly add the distinct values already in the first list in ascending order to the second list and add the corresponding frequencies of those values to the first list.

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15, 18, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 18, 20
Offset: 1

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Author

Keywords

Examples

			Second list begins:
  1;
  1;
  1, 2;
  1, 2;
  1, 2, 3;
  1, 2, 3;
  1, 2, 3, 4;
  1, 2, 3, 4, 5;
  1, 2, 3, 4, 5, 6;
  1, 2, 3, 4, 5, 6, 7;
  1, 2, 3, 4, 5, 6, 7;
  1, 2, 3, 4, 5, 6, 7, 8;
  1, 2, 3, 4, 5, 6, 7, 8, 9, 11;
  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15;
  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15, 18;
  1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 18, 20;
		

Crossrefs

Cf. A030717 (1st list).

Programs

  • Mathematica
    s = t = {{1}}; Do[AppendTo[t, BinCounts[#, {1, Max[#] + 1}] &[Flatten[t]]]; AppendTo[s, Union@ Flatten@ t], {12}]; Flatten[s] (* Michael De Vlieger, Nov 15 2022, after Peter J. C. Moses at A030717 *)

Extensions

Name revised in line with A030778 by Peter Munn, Oct 11 2022