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%I M1611 #24 Oct 21 2023 01:12:17
%S 0,2,6,16,43,124,353
%N Largest subset of 3 X 3 X ... X 3 cube (in n dimensions) with no 3 points collinear.
%C 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
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H K. O'Bryant, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/OBryant/obr3.html">Sets of Natural Numbers with Proscribed Subsets</a>, J. Int. Seq. 18 (2015) # 15.7.7.
%H V. Chvatal, <a href="http://dx.doi.org/10.1016/0012-365X(73)90167-2">Edmonds polytopes and a hierarchy of combinatorial problems</a>, Discr. Math. 4 (1973) no 4, 305-337.
%H D. H. J. Polymath, <a href="http://arxiv.org/abs/1002.0374">Density Hales-Jewett and Moser numbers</a>, arXiv:1002.0374 [math.CO], 2010.
%H <a href="/index/Th#TTT">Index entries for sequences related to tic-tac-toe</a>
%K nonn,hard,more
%O 0,2
%A _N. J. A. Sloane_
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