List all perfect square numbers over 1000, employing only 2 different decimal digits. Example: 88^2=7744 will be on your list.

Ignore trivial solutions like 1 or 4 or 9 followed by an even number of zeroes.

How far can you go?

Known largest solution is a 10-digit number 6,661,661,161.

From https://oeis.org/A018884:  No other terms below 10^41.  The sequence is probably finite.

Posted by xdog on 2018-10-23 14:56:19