Writing the terms of a Recursively Defined Sequence
Write down the first five terms of the following recursively defined sequence.
s_{1}=1,\ \ \ \ \ s_{n}=n s_{n-1}The first term is given as s_{1} = 1. To get the second term, use n = 2 in the formula s_{n} = ns_{n-1} to get {s}_{2}=2{s}_{1}=2\cdot 1=2. To get the third term, use n = 3 in the formula to get s_{3}=3s_{2}=3\cdot 2=6. To get a new term requires knowing the value of the preceding term. The first five terms are
\begin{array}{c}{{s_{1}=1}}\\ {{s_{2}=2\cdot1=2}}\\ {{s_{3}=3\cdot2=6}}\\ {{s_{4}=4\cdot6=24}}\\ {{s_{5}=5\cdot24=120}}\end{array}Do you recognize this sequence? s_{n} = n!