The sequence provided is: 14, 15, 16, 17, 18, ...
This is an arithmetic sequence where the first term \( a_1 \) is 14 and the common difference \( d \) is 1 (since each term increases by 1).
The explicit formula for the \( n \)-th term of an arithmetic sequence can be given by:
\[ a_n = a_1 + (n - 1) \cdot d \]
Substituting the known values into the formula:
- \( a_1 = 14 \)
- \( d = 1 \)
We get:
\[ a_n = 14 + (n - 1) \cdot 1 \]
Simplifying this:
\[ a_n = 14 + n - 1 \]
\[ a_n = n + 13 \]
Thus, the explicit formula for the sequence is:
\[ a_n = n + 13 \]
Now, to find the fifteenth term \( a_{15} \):
\[ a_{15} = 15 + 13 = 28 \]
Therefore, the fifteenth term of the sequence is 28.