What is the number of lines that pass through the center of an n-dimensional tic-tac-toe grid?
closed as too localized by Robin Chapman, Andy Putman, Charles Siegel, François G. Dorais♦ Aug 21 '10 at 19:38
This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.
The squares tic tac toe grid can be represented with $(x^1,x^2,...,x^n)$ where each can be 0, 1 or 2.
A line passing through the center can be identified Given any coordinate except $(0,0,...,0)$.
There are $3^n-1$ possible coordinates to start a line from.
For each line through center, there will be two endpoints. This should help you get your answer.