已知数列an满足a(n+1)=2an-1,且a1=3,bn=(an-1)/ana(n+1),数列bn前n项和为sn.求sn.设f(x)=(x-2^n+1)ln(x-2^n+1)-xn为正整数,求证f(x)大于等于(3sn+2)/(6sn-2)
问题描述:
已知数列an满足a(n+1)=2an-1,且a1=3,bn=(an-1)/ana(n+1),数列bn前n项和为sn.求sn.
设f(x)=(x-2^n+1)ln(x-2^n+1)-x
n为正整数,求证f(x)大于等于(3sn+2)/(6sn-2)
答