A266626 - OEIS

A266626

Number of ON (black) cells in the n-th iteration of the "Rule 45" elementary cellular automaton starting with a single ON (black) cell.

1, 1, 4, 2, 5, 7, 8, 8, 7, 13, 9, 12, 11, 18, 15, 18, 14, 23, 16, 22, 15, 30, 23, 23, 20, 36, 18, 30, 32, 30, 30, 34, 28, 37, 33, 44, 27, 52, 25, 53, 32, 47, 38, 54, 28, 62, 36, 57, 38, 61, 43, 59, 39, 65, 43, 65, 44, 74, 51, 67, 48, 79, 40, 79, 41, 82, 50

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

REFERENCES

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

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..2500

Eric Weisstein's World of Mathematics, Elementary Cellular Automaton

S. Wolfram, A New Kind of Science

Index entries for sequences related to cellular automata

Index to Elementary Cellular Automata

MATHEMATICA

rule=45; 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[Total[catri[[k]]], {k, 1, rows}] (* Number of Black cells in stage n *)

CROSSREFS

Cf. A266619.

Sequence in context: A199625 A020849 A134235 * A159979 A198233 A169850

Adjacent sequences: A266623 A266624 A266625 * A266627 A266628 A266629

KEYWORD

nonn,easy

AUTHOR

Robert Price, Jan 01 2016

STATUS

approved