Number of 4 letter words you can put together using the letters {g,o,o,g,le}

No.12192808 ViewReplyOriginalReport
This ammoung of combinations can be easily calculated, however I am clueless about how you'd go about generalizing this. If we have a set of elements Xn, each of which is repeated (can be used) An times, how many combinations of k elements can we put together?