4 ms·

It comes from the result 4*5 = 12 is either wrong or base 18

• debugnik 5mo ago
  Makes more sense to me that 4*n here means n+7, which fits the pattern and would make her stop at 12+7=19, one short of 20, because Anglosphere countries teach multiplication tables up to 12. (I definitely didn't get this until I read the rest of the comments here. This is apparently explained in The Annotated Alice.)