There are several sequences in the OEIS that are relevant. This one almost answers your question: %I A061529 %S A061529 0,0,46080,8707262054400,9325207163130772193280000, %T A061529 282114820702333003219864073866838016000000, %U A061529 519832475166470446526522688211309314023066144499302400000000000 %N A061529 Number of complete games of n X n tic-tac-toe ending in a draw. %H A061529 J. Ferry, <a href="http://ladybug.xs4all.nl/arlet/puzzles/solutions/contrib/tictactoe.html">n X n tic-tac-toe</a> (Mathematica programs followed by results) %H A061529 <a href="http://www.research.att.com/~njas/sequences/Sindx_Th.html#TTT">Index entries for sequences related to tic-tac-toe</a> %Y A061529 Cf. A061526, A061527, A061528, A061530. %K A061529 nonn %O A061529 1,3 %A A061529 Jim Ferry (jferry@alum.mit.edu), May 04 2001 NJAS