cp's OEIS Frontend

A374421 a(n) is the smallest number which can be represented as the sum of 3 distinct positive n-th powers in exactly 2 ways, or -1 if no such number exists.

%I A374421 #7 Jul 19 2024 19:13:59
%S A374421 8,62,1009,6578,1375298099,160426514
%N A374421 a(n) is the smallest number which can be represented as the sum of 3 distinct positive n-th powers in exactly 2 ways, or -1 if no such number exists.
%C A374421 a(7) > 10^20, if it is not -1. - _Michael S. Branicky_, Jul 09 2024
%e A374421 a(5) = 1375298099 = 3^5 + 54^5 + 62^5 = 24^5 + 28^5 + 67^5.
%e A374421 a(6) = 160426514 = 3^6 + 19^6 + 22^6 = 10^6 + 15^6 + 23^6.
%Y A374421 Cf. A046881, A374418, A374422, A374423, A374424, A374425.
%K A374421 nonn,hard,more
%O A374421 1,1
%A A374421 _Ilya Gutkovskiy_, Jul 08 2024