A374228 a(n) is the smallest number which can be represented as the sum of four distinct positive n-th powers in exactly n ways, or -1 if no such number exists.
10, 90, 1521, 300834
Offset: 1
Examples
a(3) = 1521 = 1^3 + 2^3 + 8^3 + 10^3 = 1^3 + 4^3 + 5^3 + 11^3 = 4^3 + 6^3 + 8^3 + 9^3.