A317402 Number of distinct (up to rotation and reflection) tic-tac-toe positions with n tokens which allow a winning strategy for O.

0, 0, 0, 8, 5, 72, 38, 56, 23, 0

Offset

0,4

Comments

Including positions where O has already won (that is, 0 for odd n and A048245(n) for even n).

Links

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

Index entries for sequences related to tic-tac-toe

Example

a(4) = 5:
x x o   x x o   o x .   o x .   . x .
. . o   . . .   . . x   . o .   o o .
. . .   . . o   o . .   . x .   . x .

Crossrefs

Cf. A008907, A317401, A048245.

Sequence in context: A272007 A296437 A038283 * A317574 A195532 A106287

Adjacent sequences: A317399 A317400 A317401 * A317403 A317404 A317405

Keyword

fini,full,nonn

Author

Álvar Ibeas, Jul 27 2018

Status

approved