1+2+3+4+5+…+2005+2006(1−1/1004)(1−1/1005)(1−1/1006)…(1−1/2005)(1−1/2006)=_.

问题描述:

1+2+3+4+5+…+2005+2006
(1−
1
1004
)(1−
1
1005
)(1−
1
1006
)…(1−
1
2005
)(1−
1
2006
)
=______.

原式=

1+2006+2+2005+…+1003+1004
1003
1004
×
1004
1005
× 
1005
1006
… 
2004
2005
×
2005
2006
=
1003×2007
1003
2006
=4026042
故答案为:4026042.