elliptic points as cell

I want to convert elliptic curve points as cell

a=0:66;
left_side = mod(a.^2,67);

right_side = mod(a.^3+1*a-3,67);
C={};
for i = 1:length(right_side)
  I = find(left_side == right_side(i));
  for j=1:length(I)
      points = [points;a(i),a(I(j))];
      C={points}
  end
end
C=mat2cell(points)% all points

I dont know whats wrong with this

[Joel Handy]

Can you tell us exactly what doesnt work. Its generally very useful to give a statement like, "I expect ..., but what I'm getting is ...".

running the code, I get teh pretty clear error, "Undefined function or variable points." You are trying to concatinate the variable points before it exists. You need to define points before your loops.

points = [];

I suspect there are more issues but we'll need more information before I can help further.