Enigma Number 1651
Four-digit numbers I have found a 3-digit perfect square, a 3-digit perfect cube and a 4-digit triangular number that between them use 10 different digits, with no leading zero. (Triangular numbers are those that fit the formula n(n+1)/2, like 1, 3, 6, 10, 15.) I have also found a 3-digit perfect square, a 3-digit triangular …