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.

A246331 Total number of ON cells at stage 2n of two-dimensional 5-neighbor outer totalistic cellular automaton defined by "Rule 465".

Original entry on oeis.org

1, 9, 25, 49, 89, 113, 161, 233, 345, 369, 417, 489, 609, 681, 825, 1041, 1369, 1393, 1441, 1513, 1633, 1705, 1849, 2065, 2401, 2473, 2617, 2833, 3193, 3409, 3841, 4489, 5465, 5489, 5537, 5609, 5729, 5801, 5945, 6161, 6497, 6569, 6713, 6929, 7289, 7505, 7937
Offset: 0

Views

Author

N. J. A. Sloane, Aug 30 2014

Keywords

Comments

The number of ON cells at stage 2n+1 is infinite.
This is a bisection of A147562.
The sequence b(n) defined by b(n) = number of ON cells at stage n if n is even, b(n) = number of OFF cells at stage n if n is odd coincides with A147562, and has a simple formula.

References

  • S. Wolfram, A New Kind of Science, Wolfram Media, 2002; pp. 173-175.

Crossrefs

Programs

  • Mathematica
    Map[Function[Apply[Plus, Flatten[ #1]]], CellularAutomaton[{ 465, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 130]] (* then take every other term *)
    ArrayPlot /@ CellularAutomaton[{465, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 23]