1 , 4 , 9 , 61 , 52 , 63 , 94 , 46 , 18 , 1 , 121

Compare that sequence to this one:

1 , 4 , 9 , 16 , 25 , 36 , 49 , 64 , 81 , 100 , 121 , 144 

It amounts to the squares of the positive integers with the
digits reversed.  When they are single digits, or palindromes,
they are the same when the digits are reversed.  As we 
see, 100 becomes 001 and the introductory zeroes omitted.

Answer: The next perfect square is 12² or 144, so reversing
those digits gives us 441.

Edwin