%N Areas of triangle ABC, if it can be split by two straight lines through A and B, into 4 parts all with integer areas.
%F n = a+b+c+d, if d = b*c*(2*a+b+c)/(a^2-b*c) is positive integer.
%e For n=6, some triangle with that area can be divided by 2 straight lines through A and B, into 4 parts with areas (2,1,1,2) or with areas (3,1,1,1). A triangle with area 12 can be divided into parts (2,1,2,7), (3,1,3,5), (4,2,2,4) and (6,2,2,2). Triangles with area 13 or 14 cannot be divided in this way.
%A _Dragan Krejakovic_, Mar 01 2012