binary-multiple-of-n-regex.js

const regexDivisibleBy = n => {
  if (n == 1) return '^(0|1)+$';
  if (n == 2) return '^(0|1)+0$';
  if (n == 3) return '^(0*(1(01*0)*1)*)*$';
  if (n == 4) return '^(0|1)+00$';
  if (n == 5) return '^(0|1(10)*(0|11)(01*01|01*00(10)*(0|11))*1)+$';
  if (n == 6) return '^(0|(11|1(00|011*0)(00|011*0)*1)(11|1(00|011*0)(00|011*0)*1)*0)+$';
  if (n == 7) return '^(0|(10((0|11)(1|00))*(10|(0|11)01)|11)(01*0(0|101|1(1|00)((0|11)(1|00))*(10|(0|11)01)))*1)+$';
  if (n == 8) return '^(0|1)+000$';
}