A374418 a(n) is the smallest number which can be represented as the sum of 2 distinct positive n-th powers in exactly 3 ways, or -1 if no such number exists.

7, 325, 87539319

Offset: 1

Author

Ilya Gutkovskiy, Jul 08 2024

Keywords

• nonn
• bref
• hard
• more

Comments

See also comments in A338799.

Examples

			a(2) = 325 = 1^2 + 18^2 = 6^2 + 17^2 = 10^2 + 15^2.
a(3) = 87539319 = 167^3 + 436^3 = 228^3 + 423^3 = 255^3 + 414^3.
		

Links

• Wikipedia, Lander, Parkin, and Selfridge conjecture

Crossrefs

Cf. A046881, A338799, A374421, A374422, A374423, A374424, A374425.