A195624 - OEIS

%I #20 Mar 30 2012 17:28:27

%S 3,9,29,93,279

%N Minimum number of squares removed from an n-dimensional tic-tac-toe board to make winning impossible for either player.

%C A156989 is the main sequence for this entry. Related to the density Hales-Jewett theorem.

%H Steve Landsburg, <a href="http://www.thebigquestions.com/2010/04/08/blogging-tic-tac-toe-and-the-future-of-math/">Blogging, Tic Tac Toe and the Future of Math</a>

%F a(n) = 3^n - A156989(n).

%Y Cf. A156989.

%K nonn,hard

%O 2,1

%A _Charles R Greathouse IV_, Sep 26 2011