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
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.
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