An arithmetic sequence starts out $−23,−19,−15$.  

1. What is the equation?

   Hint (a):

   What is the common difference between the terms?

   More Help (a):

   Remember that the first term is $-23$. What is the 0th term?

2. How many times must the generator be applied so that the result is greater than $\text{10,000}$?

   Hint (b):

   Use the rule you found in part (a).