[v for p,v in enumerate([sum([int(d)**len(str(i))for d in str(i)])for i in range(7**6)])if p==v]
The readability is lost, but it is even shorter.
AP Computer Science - The Armstrong Numbers
[v for p,v in enumerate([sum([int(d)**len(str(i))for d in str(i)])for i in range(7**6)])if p==v]
The readability is lost, but it is even shorter.