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.

A266382 Decimal representation of the n-th iteration of the "Rule 22" elementary cellular automaton starting with a single ON (black) cell.

Original entry on oeis.org

1, 7, 17, 119, 257, 1799, 4369, 30583, 65537, 458759, 1114129, 7798903, 16843009, 117901063, 286331153, 2004318071, 4294967297, 30064771079, 73014444049, 511101108343, 1103806595329, 7726646167303, 18764712120593, 131352984844151, 281479271743489
Offset: 0

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Author

Robert Price, Dec 28 2015

Keywords

Comments

Empirical observation: This sequence can also be generated in Conway's Game of Life by setting the initial condition to be an infinite row of ON cells in both directions. After each iteration, rows of cells turned ON will be labeled as 1 and rows that are OFF will be labeled 0. When the resulting binary number is converted to decimal notation, the resulting sequence is the same as A266382. [Brook Estifanos, Mar 09 2016]

References

  • S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

Crossrefs

Cf. A071029.

Programs

  • Mathematica
    rule=22; rows=30; 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]],2],{k,1,rows}] (* Decimal Representation of Rows *)