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a(n) is the smallest positive integer whose square can be represented as the sum of 3 distinct nonzero squares in exactly n ways, or -1 if no such number exists.
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%I #11 Aug 12 2024 01:25:40

%S 1,7,15,23,31,21,33,39,49,45,79,57,95,103,75,69,127,87,63,151,93,167,

%T 111,123,99,187,117,105,161,241,141,135,153,247,271,283,177,183,165,

%U 275,147,171,323,219

%N a(n) is the smallest positive integer whose square can be represented as the sum of 3 distinct nonzero squares in exactly n ways, or -1 if no such number exists.

%H <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>

%e a(3) = 23: 23^2 = 3^2 + 6^2 + 22^2 = 3^2 + 14^2 + 18^2 = 6^2 + 13^2 + 18^2.

%Y Cf. A006339, A025415, A025442, A346071.

%K nonn,more

%O 0,2

%A _Ilya Gutkovskiy_, Jul 20 2024

%E a(35)-a(43) from _Michael S. Branicky_, Jul 21 2024