How do you find the nth term rule for 1,5,9,13,...?

Mar 5, 2018

${a}_{n} = 4 n - 3$

Explanation:

Due to $r = 5 - 1 = 4$ and ${a}_{1} = 1$

${a}_{n} = r \cdot \left(n - 1\right) + {a}_{1}$

=$4 \cdot \left(n - 1\right) + 1$

=$4 n - 3$