OFFSET
1,3
COMMENTS
This means no three on any line, not just lines in the X or Y directions.
REFERENCES
M. A. Adena, D. A. Holton and P. A. Kelly, Some thoughts on the no-three-in-line problem, pp. 6-17 of Combinatorial Mathematics (Proceedings 2nd Australian Conf.), Lect. Notes Math. 403, 1974.
R. K. Guy, Unsolved combinatorial problems, pp. 121-127 of D. J. A. Welsh, editor, Combinatorial Mathematics and Its Applications. Academic Press, NY, 1971.
R. K. Guy and P. A. Kelly, The No-Three-Line Problem. Research Paper 33, Department of Mathematics, Univ. of Calgary, Calgary, Alberta, 1968. Condensed version in Canad. Math. Bull. Vol. 11, pp. 527-531, 1968.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Benjamin Chaffin, No-Three-In-Line Problem.
A. Flammenkamp, Progress in the no-three-in-line problem
A. Flammenkamp, Solutions of the no-three-in-line problem
A. Flammenkamp, Solutions of the no-three-in-line problem
M. Gardner, R. L. Graham, M. Meierruth, R. Jacobson, Correspondence, 1976
R. K. Guy and P. A. Kelly, The No-Three-Line Problem, Research Paper 33, Department of Mathematics, Univ. of Calgary, Calgary, Alberta, 1968. [Annotated scanned copy]
R. K. Guy and P. A. Kelly, The No-Three-Line Problem, condensed version in Canad. Math. Bull. Vol. 11, pp. 527-531, 1968. [Annotated scanned copy]
R. K. Guy, P. A. Kelly, N. J. A. Sloane, Correspondence, 1968-1971
EXAMPLE
a(3) = 2:
X X o ... o X X
X o X ... X o X
o X X ... X X o
CROSSREFS
KEYWORD
nonn,nice,more
AUTHOR
EXTENSIONS
More terms from the Achim Flammenkamp web site, May 24 2005
a(17) and a(18) from Benjamin Chaffin, Apr 05 2006
Minor edits from N. J. A. Sloane, May 25 2010
STATUS
approved