已知数列{an}满足a1=3,且a(n+1)-3an=3的n次方(n属于N*).数列{bn}满足bn=3的-n次方*an.(1)求证:数列{bn}是等差数列;(2)设Sn=a1/3+a2/4+a3/5+…+an/(n+2),求满足不等式1/128<Sn/S(2n)<0.25的所有正整数n
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![已知数列{an}满足a1=3,且a(n+1)-3an=3的n次方(n属于N*).数列{bn}满足bn=3的-n次方*an.(1)求证:数列{bn}是等差数列;(2)设Sn=a1/3+a2/4+a3/5+…+an/(n+2),求满足不等式1/128<Sn/S(2n)<0.25的所有正整数n](/uploads/image/z/6151466-2-6.jpg?t=%E5%B7%B2%E7%9F%A5%E6%95%B0%E5%88%97%7Ban%7D%E6%BB%A1%E8%B6%B3a1%3D3%2C%E4%B8%94a%28n%2B1%29-3an%3D3%E7%9A%84n%E6%AC%A1%E6%96%B9%28n%E5%B1%9E%E4%BA%8EN%2A%29.%E6%95%B0%E5%88%97%7Bbn%7D%E6%BB%A1%E8%B6%B3bn%3D3%E7%9A%84-n%E6%AC%A1%E6%96%B9%2Aan.%281%29%E6%B1%82%E8%AF%81%EF%BC%9A%E6%95%B0%E5%88%97%7Bbn%7D%E6%98%AF%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97%EF%BC%9B%EF%BC%882%EF%BC%89%E8%AE%BESn%3Da1%2F3%2Ba2%2F4%2Ba3%2F5%2B%E2%80%A6%2Ban%2F%28n%2B2%29%2C%E6%B1%82%E6%BB%A1%E8%B6%B3%E4%B8%8D%E7%AD%89%E5%BC%8F1%2F128%26amp%3Blt%3BSn%2FS%282n%29%26amp%3Blt%3B0.25%E7%9A%84%E6%89%80%E6%9C%89%E6%AD%A3%E6%95%B4%E6%95%B0n)
已知数列{an}满足a1=3,且a(n+1)-3an=3的n次方(n属于N*).数列{bn}满足bn=3的-n次方*an.(1)求证:数列{bn}是等差数列;(2)设Sn=a1/3+a2/4+a3/5+…+an/(n+2),求满足不等式1/128<Sn/S(2n)<0.25的所有正整数n
已知数列{an}满足a1=3,且a(n+1)-3an=3的n次方(n属于N*).数列{bn}满足
bn=3的-n次方*an.(1)求证:数列{bn}是等差数列;(2)设Sn=a1/3+a2/4+a3/5+…+an/(n+2),求满足不等式1/128<Sn/S(2n)<0.25的所有正整数n的值
已知数列{an}满足a1=3,且a(n+1)-3an=3的n次方(n属于N*).数列{bn}满足bn=3的-n次方*an.(1)求证:数列{bn}是等差数列;(2)设Sn=a1/3+a2/4+a3/5+…+an/(n+2),求满足不等式1/128<Sn/S(2n)<0.25的所有正整数n
mark,求真相
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