Your friend asks you to help him with his dog grooming business and will pay you 4 pennies for the first job. You agree to help if he quadruples your payment for each job completed. After 2 grooming jobs, you will receive 16 pennies, and after 3 grooming jobs, you will receive 64 pennies. Complete and solve the equation that finds the number of pennies he will pay you after the 9th dog grooming job.