login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A267802 Decimal representation of the n-th iteration of the "Rule 213" elementary cellular automaton starting with a single ON (black) cell. 1
1, 3, 19, 115, 499, 2035, 8179, 32755, 131059, 524275, 2097139, 8388595, 33554419, 134217715, 536870899, 2147483635, 8589934579, 34359738355, 137438953459, 549755813875, 2199023255539, 8796093022195, 35184372088819, 140737488355315, 562949953421299 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

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

LINKS

Robert Price, Table of n, a(n) for n = 0..1000

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

FORMULA

Conjectures from Colin Barker, Jan 21 2016: (Start)

a(n) = 5*a(n-1)-4*a(n-2) for n>3.

G.f.: (1+2*x)*(1-4*x+16*x^2) / ((1-x)*(1-4*x)).

(End)

Conjecture: a(n) = 2^(2*n+1) - 13 for n>1. - Colin Barker, Nov 25 2016

MATHEMATICA

rule=213; 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]], 2], {k, 1, rows}] (* Decimal Representation of Rows *)

CROSSREFS

Cf. A267800.

Sequence in context: A037774 A037662 A116979 * A229928 A309183 A261777

Adjacent sequences:  A267799 A267800 A267801 * A267803 A267804 A267805

KEYWORD

nonn

AUTHOR

Robert Price, Jan 20 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 15 22:06 EDT 2021. Contains 345053 sequences. (Running on oeis4.)