Given that the sum of the first n terms of the sequence {an} is Sn, and 2Sn = 3an-1, n *, find the general term formula of an
Because 2Sn = 3an-1
So 2Sn + 1 = 3an + 1 - 1
The bottom minus the top
2an+1=3an+1 - 3an-1
So an + 1 = 3an-1
So the equal ratio sequence is 3
Substituting 2Sn = 3an-1 into n = 1
So A1 = 1, so an = 3 ^ n-1
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