Answer
$a_n=50-13n$
Work Step by Step
We know that the general formula of an arithmetic sequence is given by $a_n= a_1+(n-1) d$
Here, we have $a_1=37 ; d=-13$
$a_n=37+(n-1) \times (-13)$
This gives: $a_n=37-13n+13$
Hence, $a_n=50-13n$