

A160416


Number of "ON" cells at nth stage in simple 2dimensional cellular automaton (see Comments for precise definition).


3




OFFSET

0,3


LINKS

Table of n, a(n) for n=0..9.
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n1)1) for n >= 2.]
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS


EXAMPLE

If we label the generations of cells turned ON by consecutive numbers we get the cell pattern shown below:
..9...9...9...9...9
...888.888.888.888.
...878.878.878.878.
...886668666866688.
..9..656.656.656..9
...886644464446688.
...878.434.434.878.
...886644222446688.
..9..656.212.656..9
000000000022446688.
0000000000.434.878.
000000000064446688.
000000000056.656..9
000000000066866688.
0000000000.878.878.
0000000000.888.888.
00000000009...9...9
0000000000.........
0000000000.........


CROSSREFS

Cf. A139250, A139251, A152980, A153006, A160117, A160118, A160410, A160412, A160414.
Cf. A160796, A161417. [From Omar E. Pol, Jun 14 2009]
Sequence in context: A051791 A243975 A160796 * A056873 A303883 A304889
Adjacent sequences: A160413 A160414 A160415 * A160417 A160418 A160419


KEYWORD

nonn


AUTHOR

Omar E. Pol, May 20 2009, Jun 14 2009


STATUS

approved



