September 23

Homework:

• Each next line is obtained from the previous one using a simple rule. Find it! Add 2-3 more lines using that rule:
  1
  1 1
  2 1
  1 2 1 1
  1 1 1 2 2 1
  3 1 2 2 1 1
  .....
  
• Out of 1000 numbers, starting with 0 and ending with 999, how many do not have digit 3 in them?
  
• Find midpoints of the intervals:
• [-7, 1000]
• [-1000, -7]