Consider that 7^2 is 49, which is written as a concatenation of 2^2 and 3^2.
Consider the sqrt of the next concatenation of squares
sqrt(4916) = 70.1...
And the next
sqrt(491625) = 701.114...
And the next
sqrt(49162536) = 7011.5
And the next
sqrt(4916253649) = 70116.0...
What's happening here?