OFFSET
0,2
COMMENTS
Alternatively, list of ternary words obtained by expanding (1+2x)^n mod 3 and reading the coefficients starting with the highest order term.
Arises in the study of a cellular automaton whose cells are in one of three states: 0, 1, or 2.
EXAMPLE
The coefficient lists of the first few polynomials are:
[1]
[2, 1]
[1, 1, 1]
[2, 0, 0, 1]
[1, 2, 0, 2, 1]
[2, 2, 2, 1, 1, 1]
[1, 0, 0, 1, 0, 0, 1]
[2, 1, 0, 2, 1, 0, 2, 1]
[1, 1, 1, 1, 1, 1, 1, 1, 1]
[2, 0, 0, 0, 0, 0, 0, 0, 0, 1]
...
MAPLE
M:=20;
F:=2+x mod 3;
g:=n->expand(F^n) mod 3;
g2:=n->series(g(n), x, M+6);
for n from 0 to M do lprint(seriestolist(g2(n))); od:
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 21 2015
STATUS
approved