9, 61, 52, 63, 94, ___ , 18 ?

it's a series of squares with digits of each number reversed.

9 --> 9 = 3²
61-->16 = 4²
52-->25 = 5²
63-->36 = 6²
94-->49 = 7²
__
18-->81 = 9²

the number in the blank is 8² with digits reversed, i.e.
8² = 64 --> 46

so the series should read: 9, 61, 52, 63, 94, 46, 18