Mathematics

The key here is recognizing that $U_n$ is a formula that tells you exactly how to build each term—just substitute the position number $n$ into the expression. Since you want the first 5 terms, you'll plug in $n = 1, 2, 3, 4, 5$ one at a time. Each substitution gives you a single number, and together they form your sequence.

The key here is recognizing that $U_n$ is a formula that tells you exactly how to build each term—just substitute the position number $n$ into the expression. Since you want the first 5 terms, you'll plug in $n = 1, 2, 3, 4, 5$ one at a time. Each substitution gives you a single number, and together they form your sequence.