How many integers between 1 and 1000, both excluded, can be expressed as the difference of the squares of 2 non negative integers?

1) 749
2) 750
3) 748
4) NOT

• 748 numbers
  
  all odd numbers ...500
  all numbers of 4k ..250
  
  1 and 1000 excluded
  total desired integers = 500+250-2=748
• 12 years agoHelpfull: Yes(0) No(1)