I wouldn't say special, it's to be expected. The problem is going from the A=1, B=C cell, to the factor cells. Dealing with the C^2 cell, this problem is ^2 as hard. We know the D=C, A=C,B=C cell, or the D=C, A=1, B=C^2 cell, but finding the factors is again, ^2 as hard.
We can step through factors by X–, A++, but again this is useless when C is the size of an RSA number. We need a magic way to predict N, or predict X.
Here's a view of (E,N,X) only showing the first cell in every cell. Honestly, I didn't expect this, and it's annoying.
You can't predict X with a given E and N.