Answer: 18
Step-by-step explanation: It's basically just the perfect square sequence with each term reversed. Here's them side-by-side:
Your sequence: 1, 4, 9, 61, 52, 63, 94, 46
Square sequence: 1, 4, 9, 16, 25, 36, 49, 64
So the next perfect square is 81, and that reversed is 18.