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.

Showing 1-2 of 2 results.

A071029 Triangle read by rows giving successive states of cellular automaton generated by "Rule 22".

Original entry on oeis.org

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

Views

Author

Hans Havermann, May 26 2002

Keywords

Comments

Row n has length 2n+1.

Examples

			From _Michael De Vlieger_, Oct 05 2015: (Start)
First 8 rows, replacing "0" with "." for better visibility of ON cells:
                1
              1 1 1
            1 . . . 1
          1 1 1 . 1 1 1
        1 . . . . . . . 1
      1 1 1 . . . . . 1 1 1
    1 . . . 1 . . . 1 . . . 1
  1 1 1 . 1 1 1 . 1 1 1 . 1 1 1
1 . . . . . . . . . . . . . . . 1
(End)
		

References

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

Crossrefs

For number of ON cells see A071044.

Programs

  • Mathematica
    clip[lst_] := Block[{p = Flatten@ Position[lst, 1]}, Take[lst, {Min@ p, Max@ p}]]; clip /@ CellularAutomaton[22, {{1}, 0}, 9] // Flatten (* Michael De Vlieger, Oct 05 2015 *)

Extensions

Corrected by Hans Havermann, Jan 07 2012

A071049 Number of 1's in n-th generation of 1-D CA using Rule 110, started with a single 1.

Original entry on oeis.org

1, 2, 3, 3, 5, 3, 5, 6, 8, 5, 6, 8, 8, 8, 11, 11, 13, 9, 11, 11, 13, 14, 16, 14, 14, 13, 13, 17, 22, 20, 16, 17, 24, 19, 14, 19, 25, 18, 20, 25, 24, 19, 24, 31, 27, 26, 24, 22, 32, 31, 28, 24, 29, 34, 30, 31, 37, 34, 34, 36, 35, 34, 35, 36, 43, 40, 36, 38, 37, 39, 40
Offset: 0

Views

Author

Hans Havermann, May 26 2002

Keywords

Comments

Number of 1's in n-th row of triangle in A070887.
Although the initial behavior is chaotic, it is an astonishing fact, pointed out by Wolfram [2002, p. 39], that after about three thousand terms all the irregularities disappear. - N. J. A. Sloane, May 15 2015

References

  • Matthew Cook, A Concrete View of Rule 110 Computation, in "The Complexity of Simple Programs", T. Neary, D. Woods, A. K. Seda, and N. Murphy (Eds.), 2008, pp. 31-55.
  • S. Wolfram, A New Kind of Science, Wolfram Media, 2002; Chapter 3.

Crossrefs

Programs

Formula

For n >= 2854, a(n+469) = -a(n+453) + a(n+256) + a(n+240) + a(n+229) + a(n+213) - a(n+16) - a(n). - N. J. A. Sloane, May 15 2015

Extensions

Added references and links. - N. J. A. Sloane, Aug 09 2014
Changed offset to make consistent with A070952, etc. - N. J. A. Sloane, Aug 15 2014
Showing 1-2 of 2 results.