In your class, you have started lessons about arithmetic progression. Since you are also a programmer, you have decided to write a function that will return the first n elements of the sequence with the given common difference d and first element a. Note that the difference may be zero!
The result should be a string of numbers, separated by comma and space.
# first element: 1, difference: 2, how many: 5
arithmetic_sequence_elements(1, 2, 5) == "1, 3, 5, 7, 9"