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%I #34 Jan 07 2020 11:34:59
%S 1,4,6,11,17,24,28,32,40,47,57,66,78,90
%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 row or column.
%C This sequence is a 2-dimensional generalization of A003002 ("no 3-term arithmetic progressions").
%e Up to 66 points (x) may be placed on a 12 X 12 point grid. Example with two symmetry axes:
%e x x . x x . . . . x x .
%e x . x . . x x . . x . x
%e . x x . . . . x x . x x
%e x . . . . x x . x x . .
%e x . . . x . x x . x . .
%e . x . x . . . x x . x .
%e . x . x x . . . x . x .
%e . . x . x x . x . . . x
%e . . x x . x x . . . . x
%e x x . x x . . . . x x .
%e x . x . . x x . . x . x
%e . x x . . . . x x . x x
%Y Cf. A003002, A193838, A300131.
%K nonn,hard,more,nice
%O 1,2
%A _Heinrich Ludwig_, Dec 13 2017
%E a(13)-a(14) from _Bert Dobbelaere_, Jan 06 2020
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