KöMaL 2009 B4216

Find all perfect squares of the form $\underbrace{aaa\dots a}_{n\ digits} \underbrace{bbb\dots b}_{n\ digits}$ .

Official text KöMaL. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.