Talk:2021 Fall AMC 12B Problems/Problem 17
Solution 3
$$ (Error compiling LaTeX. Unknown error_msg)
Use generating function, define 
be 
ways for the end point be 
unit away from the origins.
$$ (Error compiling LaTeX. Unknown error_msg)
Therefore,
if the current point is origin, need to 
\\if the current point on vertex of the unit hexagon, need to 
, where there is one way to return to the origin and there are two ways to keep distance = 1
\\Now let's start
\\init 
;
\\1st step: 
\r\n
\\2nd step: 
\\3rd step: 
\\4th step: 
\\5th step: 
\\So there are 
ways for the bug never moves more than 1 unit away from orign, and 
% \\-wwei.yu \end{left}
