

A003142


Largest subset of 3 X 3 X ... X 3 cube (in n dimensions) with no 3 points collinear.
(Formerly M1611)


2




OFFSET

0,2


COMMENTS

The D. H. J. Polymath collective found a(5) and a(6) and gives the bound a(n) >= (2 + o(1))binomial(n, i)*2^i for any i (and note that this is maximized by i near 2n/3).  Charles R Greathouse IV, Jun 11 2013


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=0..6.
K. O'Bryant, Sets of Natural Numbers with Proscribed Subsets, J. Int. Seq. 18 (2015) # 15.7.7
V. Chvatal, Edmonds polytopes and a hierarchy of combinatorial problems, Discr. Math. 4 (1973) no 4, 305337.
D. H. J. Polymath, Density HalesJewett and Moser numbers, arXiv:1002.0374 [math.CO]
Index entries for sequences related to tictactoe


CROSSREFS

Sequence in context: A319503 A295572 A027068 * A118041 A105073 A002605
Adjacent sequences: A003139 A003140 A003141 * A003143 A003144 A003145


KEYWORD

nonn,hard,more


AUTHOR

N. J. A. Sloane.


STATUS

approved



