The checkerboard pattern is simply because I find it easier to measure out taxicab distances when the diagonals are colored in. Feel free to remove the shading if you'd prefer.
(Some clue(s) are probably not needed for the solve, but were included for symmetry and aesthetics.)
Solution code: Clockwise, the cells that are a taxi-cab distance of 5 away from R5C5, starting from the 5. (16-digits)
on 19. February 2021, 11:22 by cdwg2000
Very nice,Beautiful sign!
on 8. December 2020, 00:12 by marcmees
very tough. Nice.
on 7. December 2020, 05:29 by puzzlemuncher69
i ended up using all of the clues at least once :) not sure if that means they're necessary but at least helpful to the logic !
nice puzzle