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 14 2016 and Apr 19 2019: (Start)
a(n) = 17*a(n-2)-16*a(n-4) for n>8.
G.f.: (1+3*x+11*x^2-4*x^3+36*x^4-176*x^5+16*x^6+192*x^7-64*x^8) / ((1-x)*(1+x)*(1-4*x)*(1+4*x)).
(End)
MATHEMATICA
rule=125; 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
KEYWORD
nonn,easy
AUTHOR
Robert Price, Jan 13 2016
EXTENSIONS
Removed an unjustified claim that Colin Barker's conjectures are correct. Removed a program based on a conjecture. - Michael De Vlieger, Jun 13 2022
STATUS
approved