Amazon coding problem : Count No. of Hops

This is the link to the problem. I am not getting why we cannot think this problem as a classical coin change dp problem where we have 1,2,3 as the changes available and N as the sum .

Please if anyone can clarify this doubt of mine?

Thanks in advance

Just saw one difference. In coin problem 1-1-2, 2-1-1, 1-2-1 are all same, but in this problem different.