Powerful numbers (4,8,9,16,25,27... )are defined as follows: if a prime p divides n then p2 must also divide n.
(8,9) is a couple of two consecutive numbers,both of them being powerful.
Find another pair(s) like that.
The more the merrier!!
(In reply to Definition
Wolfram Math's definition:
An integer m such that if p divides m then p^2 divides m , is called a powerful number.
is not differentt from mine.