We are given a sequence $a_n$ such that $a_1 = 2$ and $a_{n+1} = 3a_n + 4$. We need to find the general term $a_n$.
2025/3/11
1. Problem Description
We are given a sequence such that and . We need to find the general term .
2. Solution Steps
First, let's rewrite the recurrence relation as
.
.
Comparing with the original relation , we have , which gives .
Therefore, .
Let . Then .
This means that the sequence is a geometric sequence with common ratio
3. Since $b_1 = a_1 + 2 = 2 + 2 = 4$, we have $b_n = b_1 \cdot 3^{n-1} = 4 \cdot 3^{n-1}$.
Therefore, , which gives .