A048246 Number of distinct 3-colorings (X, O and blank) of 3 X 3 grid with floor((n+1)/2) X's, floor(n/2) O's and 9 - n blanks.

1, 3, 12, 38, 108, 174, 228, 174, 89, 23

Offset

0,2

Comments

Number of tic-tac-toe positions after n plays if game is allowed to continue after the win, up to rotation and reflection. Gives upper bound on distinct tic-tac-toe positions after n plays (A008907).

Links

Table of n, a(n) for n=0..9.

Index entries for sequences related to tic-tac-toe

Crossrefs

Cf. A008907, A048245.

Sequence in context: A319077 A368097 A008907 * A320203 A217093 A278639

Adjacent sequences: A048243 A048244 A048245 * A048247 A048248 A048249

Keyword

nonn,fini,full

Author

Rob Pratt

Status

approved