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.

A075437 Triangle read by rows giving successive iterations of the Rule 110 elementary cellular automaton starting with a single black (1) cell where row n is of length 2n+1.

Original entry on oeis.org

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

Views

Author

Eric W. Weisstein, Sep 15 2002

Keywords

Comments

The right n terms in a(n) are all 0.
T(n,k) = A070887(n+1,k+1), k=0..n. - Reinhard Zumkeller, Jun 26 2013

Examples

			      1;
    1,1,0;
  1,1,1,0,0;
1,1,0,1,0,0,0; ...
		

References

  • S. Wolfram, A New Kind of Science. Champaign, IL: Wolfram Media, p. 31ff, 2002.

Crossrefs

Cf. A070887.

Programs

  • Haskell
    a075437 n k = a075437_tabf !! n !! k
    a075437_row n = a075437_tabf !! n
    a075437_tabf = iterate rule110 [1] where
       rule110 row = f ([0,0] ++ row ++ [0,0]) where
           f [,]          = []
           f (:ws@(0:0:)) = 0 : f ws
           f (1:ws@(1:1:_)) = 0 : f ws
           f (:ws@(:_:_)) = 1 : f ws
    -- Reinhard Zumkeller, Jun 26 2013
  • Mathematica
    A075437list[rowmax_]:=MapIndexed[ArrayPad[#1,#2-rowmax-1]&,CellularAutomaton[110,{{1},0},{rowmax,All}]];A075437list[10] (* Generates 11 rows *) (* Paolo Xausa, Oct 04 2023 *)