West London reader Richard England has been looking at the arcane subject of "squares consisting entirely of two-digit primes".
There are very few of these numbers, the lowest being 4,761, which is 692 (primes with a leading zero such as 03 not being taken into account).
Richard's first question is: What is the lowest six-digit square of this type? Then his main problem is: What is the lowest eight-digit square that consists of four two-digit primes?
See the answer to find squares made of two-digit primes
This was first published in April 2008