A375335 a(n) is the smallest positive integer whose square can be represented as the sum of n distinct nonzero squares in exactly n ways, or -1 if no such integer exists.

1, 1, 25, 23, 17

Offset: 0

Author

Ilya Gutkovskiy, Aug 12 2024

Keywords

• nonn
• more

Comments

a(6) = 16, a(10) = 25; a(5) > 500, a(7..9) > 100 if not -1 - Michael S. Branicky, Aug 13 2024

Examples

			a(2) = 25: 25^2 =  7^2 + 24^2
                = 15^2 + 20^2.
.
a(3) = 23: 23^2 = 3^2 +  6^2 + 22^2
                = 3^2 + 14^2 + 18^2
                = 6^2 + 13^2 + 18^2.
.
a(4) = 17: 17^2 = 2^2 + 4^2 + 10^2 + 13^2
                = 2^2 + 5^2 +  8^2 + 14^2
                = 2^2 + 8^2 + 10^2 + 11^2
                = 3^2 + 6^2 + 10^2 + 12^2.
		

Links

• Index entries for sequences related to sums of squares

Crossrefs

Cf. A006339, A374805, A350241.