Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #21 Jan 12 2020 14:04:09
%S 1,4,6,9,16,17,21,26,31,34,40,46
%N Largest number of points that can be placed on an n X n point grid so that no point is equally distant from two other points on the same straight line.
%C This definition is a 2-dimensional generalization of A003002 ("no 3-term arithmetic progressions"). It generalizes the definition of A296468 to include not only triples on horizontal or vertical lines but on any straight line.
%e On a 10 X 10 point grid 34 points (X) can be placed at most. Example:
%e . X . . . X X . . .
%e X X . . . X X . X .
%e X . X X . . . . X .
%e . . X . . . . X . X
%e . . . . . . . . X X
%e X X . . . . . . . .
%e X . X . . . . X . .
%e . X . . . . X X . X
%e . X . X X . . . X X
%e . . . X X . . . X .
%Y Cf. A003002, A296468.
%K nonn,hard,more
%O 1,2
%A _Heinrich Ludwig_, Feb 26 2018
%E a(11) from _Bert Dobbelaere_, Jan 09 2020
%E a(12) from _Bert Dobbelaere_, Jan 12 2020