在数列an中,若a1=2,na(n+1)=(n+1)an+2(n属于N*),则a10等于

na(n+1)=(n+1)an+2 (两边同除以n(n+1) )a(n+1)/(n+1)=an/n+2/n(n+1)a(n+1)/(n+1)-an/n=2[1/n-1/(n+1)]a2/2-a1/1=2(1-1/2)a3/3-a2/2=2(1/2-1/3);a10/10-a9/9=2(1/9-1/10)上式相加得a10/10-a1/1=2(1-1/2+1/2-1/3+...+1...