A037188 Number of ways of placing 2n points on n X n grid so no 3 are in a line (solutions with symmetry about both main diagonals).

0, 0, 1, 1, 0, 2, 0, 0, 0, 1, 0, 2, 1, 3, 1, 1, 0, 2, 0, 2, 0, 1, 1, 2, 2, 0, 0, 0, 1, 1, 2, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0

Offset

1,6

Links

Table of n, a(n) for n=1..45.

A. Flammenkamp, Solutions of the no-three-in-line problem

A. Flammenkamp, Solutions of the no-three-in-line problem

A. Flammenkamp, Progress in the no-three-in-line problem, J. Combinat. Theory A 60 (1992), 305-311.

A. Flammenkamp, Progress in the no-three-in-line problem. II, J. Combin. Theory Ser. A 81 (1998), no. 1, 108-113.

Crossrefs

Cf. A000769.

Sequence in context: A367783 A363808 A227761 * A276847 A271231 A306798

Adjacent sequences: A037185 A037186 A037187 * A037189 A037190 A037191

Keyword

nonn,more

Author

N. J. A. Sloane.

Extensions

More terms from Flammenkamp web site, May 24 2005

Status

approved