设数列﹛an﹜满足:a₁=1,an+1=3an,n∈N+,(Ⅰ)求﹛an﹜的通项公式及前n项和Sn﹙Ⅱ﹚已知﹛bn﹜是等差数列,Tn为前n项和,且b₁=a₂,b₃=a₁+a₂+a₃,求T20. 注:n+1是下标,n也
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![设数列﹛an﹜满足:a₁=1,an+1=3an,n∈N+,(Ⅰ)求﹛an﹜的通项公式及前n项和Sn﹙Ⅱ﹚已知﹛bn﹜是等差数列,Tn为前n项和,且b₁=a₂,b₃=a₁+a₂+a₃,求T20. 注:n+1是下标,n也](/uploads/image/z/1549981-37-1.jpg?t=%E8%AE%BE%E6%95%B0%E5%88%97%EF%B9%9Ban%EF%B9%9C%E6%BB%A1%E8%B6%B3%EF%BC%9Aa%26%238321%3B%3D1%2Can%2B1%3D3an%2Cn%E2%88%88N%2B%2C%EF%BC%88%E2%85%A0%EF%BC%89%E6%B1%82%EF%B9%9Ban%EF%B9%9C%E7%9A%84%E9%80%9A%E9%A1%B9%E5%85%AC%E5%BC%8F%E5%8F%8A%E5%89%8Dn%E9%A1%B9%E5%92%8CSn%EF%B9%99%E2%85%A1%EF%B9%9A%E5%B7%B2%E7%9F%A5%EF%B9%9Bbn%EF%B9%9C%E6%98%AF%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97%2CTn%E4%B8%BA%E5%89%8Dn%E9%A1%B9%E5%92%8C%2C%E4%B8%94b%26%238321%3B%EF%BC%9Da%26%238322%3B%2Cb%26%238323%3B%3Da%26%238321%3B%2Ba%26%238322%3B%2Ba%26%238323%3B%2C%E6%B1%82T20.+++%E6%B3%A8%3An%2B1%E6%98%AF%E4%B8%8B%E6%A0%87%2Cn%E4%B9%9F)
设数列﹛an﹜满足:a₁=1,an+1=3an,n∈N+,(Ⅰ)求﹛an﹜的通项公式及前n项和Sn﹙Ⅱ﹚已知﹛bn﹜是等差数列,Tn为前n项和,且b₁=a₂,b₃=a₁+a₂+a₃,求T20. 注:n+1是下标,n也
设数列﹛an﹜满足:a₁=1,an+1=3an,n∈N+,(Ⅰ)求﹛an﹜的通项公式及前n项和Sn
﹙Ⅱ﹚已知﹛bn﹜是等差数列,Tn为前n项和,且b₁=a₂,b₃=a₁+a₂+a₃,求T20. 注:n+1是下标,n也是下标
设数列﹛an﹜满足:a₁=1,an+1=3an,n∈N+,(Ⅰ)求﹛an﹜的通项公式及前n项和Sn﹙Ⅱ﹚已知﹛bn﹜是等差数列,Tn为前n项和,且b₁=a₂,b₃=a₁+a₂+a₃,求T20. 注:n+1是下标,n也