OFFSET
0,2
LINKS
Robert Price, Table of n, a(n) for n = 0..1000
Eric Weisstein's World of Mathematics, Elementary Cellular Automaton
Stephen Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
Conjectures from Colin Barker, Jan 15 2016 and Apr 19 2019: (Start)
a(n) = 10001*a(n-2) - 10000*a(n-4) for n > 5.
G.f.: (1+10*x)*(1 - 9901*x^2 + 20000*x^4) / ((1-x)*(1+x)*(1-100*x)*(1+100*x)).
(End)
MATHEMATICA
rule=133; 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]]], {k, 1, rows}] (* binary representation of rows *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Robert Price, Jan 15 2016
STATUS
approved