A374423 a(n) is the smallest number which can be represented as the sum of 3 distinct positive n-th powers in exactly 4 ways, or -1 if no such number exists.
10, 161, 13896, 5978882
Offset: 1
Examples
a(3) = 13896 = 1^3 + 12^3 + 23^3 = 2^3 + 4^3 + 24^3 = 4^3 + 18^3 + 20^3 = 9^3 + 10^3 + 23^3. a(4) = 5978882 = 3^4 + 40^4 + 43^4 = 8^4 + 37^4 + 45^4 = 15^4 + 32^4 + 47^4 = 23^4 + 25^4 + 48^4.