第n项是n×(n+1)=n²+n
所以原式=(1²+1)+(2²+2)+……+(2002²+2003)
=(1²+2²+3²+……+2002²)+(1+2+……+2003)
=2002×(2002+1)×(2×2002+1)/6 + 2003×(2003+1)/2
=2678686011
第n项是n×(n+1)=n²+n
所以原式=(1²+1)+(2²+2)+……+(2002²+2003)
=(1²+2²+3²+……+2002²)+(1+2+……+2003)
=2002×(2002+1)×(2×2002+1)/6 + 2003×(2003+1)/2
=2678686011