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.

A071033 a(n) = n-th state of cellular automaton generated by "Rule 94" when started with a single ON cell.

Original entry on oeis.org

1, 111, 11011, 1110111, 110101011, 11101010111, 1101010101011, 111010101010111, 11010101010101011, 1110101010101010111, 110101010101010101011, 11101010101010101010111, 1101010101010101010101011, 111010101010101010101010111, 11010101010101010101010101011
Offset: 0

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Author

Hans Havermann, May 26 2002

Keywords

Comments

a(n) has length 2n+1.

Crossrefs

This sequence, A118101 and A118102 are equivalent descriptions of the Rule 94 automaton.

Programs

  • Mathematica
    rule=94; rows=20; ca=CellularAutomaton[rule, {{1}, 0}, rows-1, {All, All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]], {rows-k+1, rows+k-1}], {k, 1, rows}]; (* Truncated list of each row *) Table[FromDigits[catri[[k]]], {k, 1, rows}]   (* Binary Representation of Rows *) (* Robert Price, Feb 21 2016 *)

Formula

Conjecture: a(n) = floor((1099*100^n + 9090)/990) + 1 for odd n > 1; a(n) = floor((1090*100^n + 10)/990) + 1 for even n > 1. - Karl V. Keller, Jr., Oct 25 2021

Extensions

Corrected by Hans Havermann, Jan 07 2012
Edited by N. J. A. Sloane, Oct 20 2015 at the suggestion of Michael De Vlieger and Kevin Ryde
More terms from Robert Price, Dec 06 2015