13.1E: Sequences and Their Notations (Exercises)
1. Write the first four terms of the sequence defined by the recursive formula \(a_{1}=2, \quad a_{n}=a_{n-1}+n .\)
2. Evaluate \(\frac{6 !}{(5-3) ! 3 !}\).
3. Write the first four terms of the sequence defined by the explicit formula \(a_{n}=10^{n}+3\).
4. Write the first four terms of the sequence defined by the explicit formula \(a_{n}=\frac{n !}{n(n+1)}\)