You have heard me teach things that have been confirmed by many reliable witnesses. Now teach these truths to other trustworthy people who will be able to pass them on to others.
Did you see the FOUR generations of discipleship at work in this verse?
3. Those whom Timothy will disciple.
4. Those whom Timothy's disciples will disciple.
And by implication from what we learn below, you could very well imply that FIVE generations of disciples are made manifest in 2 Timothy 2:2.
1 Corinthians 15:3
I passed on to you what was most important and what had also been passed on to me. Christ died for our sins, just as the Scriptures said.
Paul had it passed to him and he passed it along to Timothy who was instructed to pass it along to others who would pass it along to others.