If the first n terms of sequence an and Sn = log3 (n + 1), then the general term formula of sequence an is

If the first n terms of sequence an and Sn = log3 (n + 1), then the general term formula of sequence an is

loga（b）-loga（c）=loga（b/c）
So when n is greater than 1, an = sn-sn-1 = log3 (n + 1 / N)
When n = 1, A1 = S1 = log3 (2)
So an = log3 (n + 1 / N)

An = (- 1 / 4) ^ n, let BN = log the logarithm of the absolute value of an with 4 as the base
How much is BN = - N, 1 / BN * BN + 1

an=(-1/4)ⁿ
bn=log4|(-1/4)ⁿ|=log4[(1/4)ⁿ]=-n
1/[bnb(n+1)]
=1/[(-n)(-(n+1)]
=1/[n(n+1)]
=1/n - 1/(n+1)

The items of the equal ratio sequence an are decreasing equal ratio sequence of positive numbers. The sequence BN satisfies BN = log2 as the logarithm of the base an, and B1 + B2 + B3 = 3, b1b2b3 = - 3. Find the general term an

This is a second-hand theorem. If an is an equal ratio sequence and BN satisfies the logarithm of an with BN = log2 as the base, then BN is an equal difference sequence. First, according to B1 + B2 + B3 = 3 and b1b2b3 = - 3, we can find BN and then find an

It is known that the sequence {an} is an equal ratio sequence. Try to judge whether the sequence {BN} composed of the sum of K terms of the sequence is still an equal ratio sequence?
Let BN = a (n-1) K + 1 + a (n-1) K + 2 + + ank, I don't understand. Why is it set like this?
Please explain what a (n-1) K + 1, a (n-1) K + 2 and an K mean,

Let B1 = a1 + A2 +... + AK, B2 = a (K + 1) + a (K + 2) +. + a (2k) (subscript in brackets), then BN = a [(n-1) K + 1] + a [(n-1) K + 2] +... A (NK) (subscript after a)
That is to say, the term in BN sequence is the sum of K terms in an sequence
B1 is the sum of the first term to the k-term of an sequence
B2 is the sum of an sequence from K + 1 to 2K
B3 is the sum of an sequence from 2K + 1 to 3K
And so on
BN is the sum of an sequence from (n-1) K + 1 to NK
Therefore, with the above settings, it is easy to get that BN is still an equal ratio sequence and the ratio is the K power of the ratio of an sequence
Note a (n-1) K + 1, a (n-1) K + 2, and an K denote the (n-1) K + 1, the (n-1) K + 2, and the NK term in the sequence {an} respectively