C1/B1=A2=3,C1/B1+C2/B2=3+C2/3=A3=5,得C2=2*B2,C1/B1+C2/B2+C3/B3=3+2+C3/B3=A4=7,得C3=2*B3,所以:C1=3,C2=2*B2=2*3^(n-1)=6,C3=2*B3=3^(n-1)=18 ------C1+(C2+C3+C4+ +C2007)=C1+2*(B2+B3+B4+ +B2007)=3+2*3*(1-3^2006)/(1-3)