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.

A071032 Triangle read by rows giving successive states of cellular automaton generated by "Rule 86".

Original entry on oeis.org

1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1
Offset: 0

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Author

Hans Havermann, May 26 2002

Keywords

Comments

Row n has length 2n+1.

References

  • S. Wolfram, A New Kind of Science, Wolfram Media, 2002; Chapter 3.

Crossrefs

Cf. A005408 (row lengths), A070952 (row sums), A051023 (central terms), A070950 (mirror image, rule 30), A226464 (complemented, rule 149).

Programs

  • Haskell
    a071032 n k = a071032_tabf !! n !! k
    a071032_row n = a071032_tabf !! n
    a071032_tabf = map reverse a070950_tabf
    -- Reinhard Zumkeller, Jun 08 2013
  • Mathematica
    A071032list[rowmax_]:=MapIndexed[ArrayPad[#1,#2-rowmax-1]&,CellularAutomaton[86,{{1},0},rowmax]];A071032list[10] (* Generates 11 rows *) (* Paolo Xausa, Jun 01 2023 *)

Formula

T(n,k) = A070950(n,2*n+1-k), 0 <= k <= 2*n+1. - Reinhard Zumkeller, Jun 08 2013

Extensions

Corrected by Hans Havermann, Jan 07 2012