(1²/2002-2²/2002+.13²/2002-14²/2002+15²/2002=（1²-2²+3²-4²+.+13²-14²+15²）/2002=(1+(3-2)(3+2)+(5-4)(5+4)+.+(15-14)(15+14))/2002=(1+2+3+...+1...