已知数列an的通项公式为an=3^n-1,在等差数列bn中,bn>0(n属于n*),且b1+b2+b3=15,又a1+b1,a2+b2,a3+b3成等比数列.(1)求数列{bn}的通项公式(2)求数列{an乘bn}的前n项和Tn
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![已知数列an的通项公式为an=3^n-1,在等差数列bn中,bn>0(n属于n*),且b1+b2+b3=15,又a1+b1,a2+b2,a3+b3成等比数列.(1)求数列{bn}的通项公式(2)求数列{an乘bn}的前n项和Tn](/uploads/image/z/1076780-20-0.jpg?t=%E5%B7%B2%E7%9F%A5%E6%95%B0%E5%88%97an%E7%9A%84%E9%80%9A%E9%A1%B9%E5%85%AC%E5%BC%8F%E4%B8%BAan%3D3%5En-1%2C%E5%9C%A8%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97bn%E4%B8%AD%2Cbn%3E0%28n%E5%B1%9E%E4%BA%8En%2A%29%2C%E4%B8%94b1%2Bb2%2Bb3%3D15%2C%E5%8F%88a1%2Bb1%2Ca2%2Bb2%2Ca3%2Bb3%E6%88%90%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97.%EF%BC%881%EF%BC%89%E6%B1%82%E6%95%B0%E5%88%97%EF%BD%9Bbn%EF%BD%9D%E7%9A%84%E9%80%9A%E9%A1%B9%E5%85%AC%E5%BC%8F%EF%BC%882%EF%BC%89%E6%B1%82%E6%95%B0%E5%88%97%EF%BD%9Ban%E4%B9%98bn%EF%BD%9D%E7%9A%84%E5%89%8Dn%E9%A1%B9%E5%92%8CTn)
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