A018883 Least nonsquare having square residues for all moduli 2 through n.
2, 3, 12, 21, 21, 21, 60, 184, 184, 280, 280, 364, 364, 364, 1456, 3124, 3124, 5236, 5236, 5236, 5236, 17185, 17185, 25249, 25249, 25249, 25249, 49504, 49504, 49504, 49504, 49504, 49504, 49504, 49504, 233776, 233776, 233776, 233776, 364144, 364144
Offset: 2