A375331 - OEIS

A375331

a(n) is the smallest number which can be represented as the sum of 4 distinct positive n-th powers in exactly 4 ways, or -1 if no such number exists.

%I #5 Aug 12 2024 13:10:34

%S -1,142,4445,300834

%N a(n) is the smallest number which can be represented as the sum of 4 distinct positive n-th powers in exactly 4 ways, or -1 if no such number exists.

%e a(4) = 300834 = 1^4 + 4^4 + 12^4 + 23^4

%e = 1^4 + 16^4 + 18^4 + 19^4

%e = 3^4 + 6^4 + 18^4 + 21^4

%e = 7^4 + 14^4 + 16^4 + 21^4.

%Y Cf. A046881, A342898, A374418, A374421, A374422, A374423, A374424, A374425, A375329, A375330, A375332, A375333, A375334.

%K sign,hard,more

%O 1,2

%A _Ilya Gutkovskiy_, Aug 12 2024