We want to find $D(3)$, $D(4)$, and $D(5)$.
Step 2:
For $n=3$, we have $D(3) = (3-1)D(3-1) + (3-2)D(3-2) = 2D(2) + 1D(1) = 2(5) + 1(3) = 10 + 3 = 13$.
For $n=4$, we have $D(4) = (4-1)D(4-1) + (4-2)D(4-2) = 3D(3) + 2D(2) = 3(13) + 2(5) = 39 + 10 = 49$.
For $n=5$,
Show more…