A195624 Minimum number of squares removed from an n-dimensional tic-tac-toe board to make winning impossible for either player.

3, 9, 29, 93, 279

Offset: 2

Author

Charles R Greathouse IV, Sep 26 2011

Keywords

• nonn
• hard

Comments

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

Links

• Steve Landsburg, Blogging, Tic Tac Toe and the Future of Math

Crossrefs

Cf. A156989.

Formula

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