A375334 a(n) is the smallest number which can be represented as the sum of 7 distinct positive n-th powers in exactly 4 ways, or -1 if no such number exists.

-1, 268, 2835, 49316, 20301007, 349717731

Offset

1,2

Links

Table of n, a(n) for n=1..6.

Example

a(6) = 349717731 = 2^6 + 6^6 +  7^6 + 17^6 + 20^6 + 22^6 + 23^6
                 = 2^6 + 8^6 + 10^6 + 11^6 + 16^6 + 21^6 + 25^6
                 = 5^6 + 8^6 + 10^6 + 11^6 + 14^6 + 23^6 + 24^6
                 = 5^6 + 8^6 + 13^6 + 14^6 + 15^6 + 16^6 + 26^6.

Crossrefs

Cf. A046881, A342901, A374418, A374421, A374422, A374423, A374424, A374425, A375329, A375330, A375331, A375332, A375333.

Sequence in context: A235175 A235169 A352474 * A330413 A251941 A286792

Adjacent sequences: A375331 A375332 A375333 * A375335 A375336 A375337

Keyword

sign,hard,more

Author

Ilya Gutkovskiy, Aug 12 2024

Status

approved