I happen to know them. Does that count as a valid answer? When I was young, we 'discovered' that repeatedly applying the procedure $abc \to a^3 + b^3 + c^3$ always ended up at one of four numbers; 370, 371,
$153 = 1^3 + 5^3 + 3^3$ or $407 = 4^3 + 0^3 + 7^3$.
For me, it's hard to forget, just like this anecdote about Hardy visiting Ramanujan:
I remember once going to see him when he was ill at Putney. I had ridden in taxi cab number 1729 and remarked that the number seemed to me rather a dull one, and that I hoped it was not an unfavourable omen. "No," he replied, "it is a very interesting number; it is the smallest number expressible as the sum of two cubes in two different ways."
($1729 = 1^3 + 12^3 = 9^3 + 10^3$)