A077725 a(n) = smallest square > 1 which can be expressed as a sum of distinct powers of n.

4, 4, 4, 25, 36, 49, 9, 9, 100, 121, 144, 169, 196, 16, 16, 289, 324, 361, 400, 441, 484, 529, 25, 25, 676, 729, 784, 841, 900, 961, 1024, 1089, 1156, 36, 36, 1369, 1444, 1521, 1600, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 49, 49, 2500, 2601, 2704, 2809, 2916