解:a(n+1)=2(1+ 1/n)²an=2[(n+1)²/n²]ana(n+1)/(n+1)²=2(an/n²)[a(n+1)/(n+1)²]/(an/n²)=2,为定值a1/1²=2/1=2数列{an/n²}是以2为首项,2为公比的等比数列an/n²=2·2ⁿ⁻¹=2ⁿan=n²·2ⁿn=1时,a1=1²·2=2,同样满足表达式数列{an}的通项公式为an=n²·2ⁿ