Wow that was absolutely pointless.. hints: -all the 4s on the edges are starter lines for the lines/columns that begin or end with 20-1-1-4, 6-1-1-4, 6-1-1-4 (go clockwise starting from top left) -now you have the frame, which consists in 3 wanna-be spirals for each border -the empty space in the middle will disappointingly host a swastika - the 5 in line 8 fits in c12-c16 Excuse my English, please.
It's completely logical, if you test the 4s on the edges, you can figure out the whole outer frame, then test the 5 in row 8 to get the inner portion. and that's not a swastika.