Final answer:
To find the nth term expression for the given sequence, observe the pattern that each term is one less than a power of 2. Thus the nth term of the sequence 1, 3, 7, 15 is given by the formula

Step-by-step explanation:
To find the expression for the nth term in an exponential sequence like 1, 3, 7, 15, we first need to understand that this does not seem to be a typical exponential sequence where each term is obtained by multiplying a fixed number with the previous term. Instead, this sequence follows a pattern where each term is one less than a power of 2 (i.e., an exponential sequence with base 2). For example,
, and so on. Thus, to find the nth term, the pattern implies that the nth term is 2^n - 1.
This can be verified by listing the terms and seeing if they match the given sequence. We have:
- 1st term:
- 1 = 1 - 2nd term:
- 1 = 3 - 3rd term:
- 1 = 7 - 4th term:
- 1 = 15
Hence, the nth term for this specific sequence can be written as T(n) =
