the vortex effect

Very nice effect! Thank you.

Too many solutions, no symmetry involved, a lot of guesswork.

The middle is perfect, but I can't get the corners right.

All the corners but the bottom left one are black.

Not logical.

Shite.

The two in column 13 is the center of the spiral that moves outward counterclockwise. make single pixel diagonals to move from one large number to the next. for the corners, keep the same spacing of the diagonals from the center.

Thank you for the tip.