cp's OEIS Frontend

A255708 No three points (i,a(i)), (j,a(j)), (k,a(k)) are collinear, for n = 0,1,2,... the value of a(n) is chosen to be m or -m (in this order) for the smallest m>=0 satisfying the condition.

%I A255708 #10 Mar 04 2015 19:45:15
%S A255708 0,0,1,1,-1,-1,4,2,2,-3,-5,-2,-7,-2,5,3,3,-5,-4,-4,6,5,-6,-3,-10,11,
%T A255708 -6,4,18,11,19,7,12,12,6,-13,19,7,-10,-7,-9,-14,13,23,-28,-8,-14,9,8,
%U A255708 -22,-9,-8,23,-11,15,22,13,8,-21,-13,-26,9,-12,-12,-11,40,21
%N A255708 No three points (i,a(i)), (j,a(j)), (k,a(k)) are collinear, for n = 0,1,2,... the value of a(n) is chosen to be m or -m (in this order) for the smallest m>=0 satisfying the condition.
%H A255708 Alois P. Heinz, <a href="/A255708/b255708.txt">Table of n, a(n) for n = 0..20000</a>
%p A255708 a:= proc(n) option remember; local i, j, k, t, ok;
%p A255708       for t from 0 do for k in [t, -t] do ok:=true;
%p A255708         for j from n-1 to 1 by -1 while ok do
%p A255708           for i from j-1 to 0 by -1 while ok do
%p A255708             ok:= (n-j)*(a(j)-a(i))<>(j-i)*(k-a(j))
%p A255708         od od; if ok then return k fi
%p A255708       od od
%p A255708     end:
%p A255708 seq(a(n), n=0..60);
%Y A255708 Cf. A005836, A179040, A231334, A236266, A236335, A255709.
%K A255708 sign,look
%O A255708 0,7
%A A255708 _Alois P. Heinz_, Mar 03 2015