已知数列{an},{bn}中,a1=b1=1,且当n≥2时,an-nan-1=0,bn=2bn-1-2n-1.记n的阶乘n(n-1)(n-2)…3?2?1≈n! (1)求数列{an}的通项公式; (2)求证:数列{}为等差数列; (3)若cn=+bn-2n,求{cn}的前n项和. |
与“已知数列{an},{bn}中,a1=b1=1,且当n≥2时,an-nan-1=0,bn=2bn-1-2n-1.记n的阶乘n(n-1)(n-2)…3•2•1≈n!(1)求数列{an}的通项公式;(2)求证:数列{bn2n}为等差数列;(3)若cn=a”考查相似的试题有: