Silver Ratio

Here we go round and round Ulam's spiral, testing each number not for primality, but if(Math.round(n/1+1.41421)*n%5==0), paint circle. Basically another twisted formatter using 1+√2 modulo 5. Why 5? Why not?

Strange things happen around this number: Square root of 2

Same calc, swapping in modulo 7. Looks a bit like a cousin to the n mod 7 image.

Go modulo 8:

Calculation per dot: (Math.round(pInt/(Math.sqrt(2)+1))%5==0)