∵ 1-
1
2 2 =
1
2 ×
3
2 =(1-
1
2 )(1+
1
2 ); 1-
1
3 2 =
2
3 ×
4
3 =(1-
1
3 )(1+
1
3 ); 1-
1
4 2 =
3
4 ×
5
4 =(1-
1
4 )(1+
1
4 ).…
∴1-
1
5 0 2 =(1-
1
50 )(1+
1
50 )=
49
50 ×
51
50 ,
1-
1
201 3 2 =(1-
1
2013 )(1+
1
2013 )=
2012
2013 ×
2014
2013 .
故答案为:
49
50 ×
51
50 ,
2012
2013 ×
2014
2013 .