

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).


1



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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,6


LINKS

Table of n, a(n) for n=1..45.
A. Flammenkamp, Solutions of the nothreeinline problem
A. Flammenkamp, Solutions of the nothreeinline problem
A. Flammenkamp, Progress in the nothreeinline problem, J. Combinat. Theory A 60 (1992), 305311.
A. Flammenkamp, Progress in the nothreeinline problem. II, J. Combin. Theory Ser. A 81 (1998), no. 1, 108113.


CROSSREFS

Cf. A000769.
Sequence in context: A056674 A336107 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



