A030686 Smallest nontrivial extension of n-th square which is a square.

16, 49, 900, 169, 256, 361, 4900, 6400, 8100, 10000, 12100, 1444, 16900, 19600, 22500, 25600, 28900, 3249, 36100, 40000, 44100, 48400, 52900, 57600, 62500, 67600, 72900, 78400, 84100, 90000, 96100, 102400, 108900, 115600, 122500