0,4

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

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

Index entries for sequences related to tic-tac-toe

a(4) = 5:

x x o x x o o x . o x . . x .

. . o . . . . . x . o . o o .

. . . . . o o . . . x . . x .

Cf. A008907, A317401, A048245.

Sequence in context: A272007 A296437 A038283 * A317574 A195532 A106287

Adjacent sequences: A317399 A317400 A317401 * A317403 A317404 A317405

fini,full,nonn

Álvar Ibeas, Jul 27 2018

approved