cp's OEIS Frontend

A186926 Maximal number of isosceles right triangles in a set of n points in the plane.

%I A186926 #26 Jan 14 2022 07:35:46
%S A186926 1,4,8,11,15,20,28,35,43,52,64,74,85,97,112,124,139,156,176,192,210,
%T A186926 229,252,271,291,314,338,363,389,417,448,473,501,531,564,594,626,659,
%U A186926 696,728,763,799,836,874,914,955,1000,1038
%N A186926 Maximal number of isosceles right triangles in a set of n points in the plane.
%C A186926 The values for n >= 15 are only conjectural.
%H A186926 Bernardo M. Abrego, Silvia Fernandez-Merchant and David B. Roberts, <a href="http://arxiv.org/abs/1102.5347">On the maximum number of isosceles right triangles in a finite point set</a>, arXiv:1102.5347 [math.CO], 2011. Also in Involve, 4:1 (2011), 27-42.
%H A186926 P. Erdős and G. Purdy, <a href="https://doi.org/10.1016/0097-3165(71)90028-8">Some extremal problems in geometry</a>, Journal of Combinatorial Theory 10 (1971), 246-252.
%H A186926 P. Erdős and G. Purdy, <a href="https://users.renyi.hu/~p_erdos/1975-40.pdf">Some extremal problems in geometry III</a>, Proc. 6th Southeastern Conference in Combinatorics, Graph Theory and Comp. (Florida Atlantic Univ., Boca Raton, Fla., 1975), pp. 291-308. Congressus Numerantium, No. XIV, Utilitas Math., Winnipeg, Man., 1975.
%H A186926 P. Erdős and G. Purdy, <a href="https://users.renyi.hu/~p_erdos/1976-43.pdf">Some extremal problems in geometry IV.</a>, Proc. 7th Southeastern Conference in Combinatorics, Graph Theory and Comp. (Louisiana State Univ., Baton Rouge, La., 1976), pp. 3.
%H A186926 Sascha Kurz, <a href="http://arxiv.org/abs/2112.12716">Plane point sets with many squares or isosceles right triangles</a>, arXiv:2112.12716 [math.CO], 2021.
%Y A186926 Cf. A051602, A186705.
%K A186926 nonn,hard
%O A186926 3,2
%A A186926 _Jonathan Vos Post_, Mar 01 2011
%E A186926 Edited by _N. J. A. Sloane_, Mar 04 2011
%E A186926 More terms from _Sascha Kurz_, Jan 14 2022