%I #13 Jul 09 2024 02:20:46

%S 37,161,498,1666,2546,7434,16609,25952,48786,49861,72347,127335,

%T 183289,196469,416913,466546,494369,506649,801010,1401011,2372586,

%U 1414009,2003027,3274986,2927260,2721677,5592756,8016592,6632759,7057914,8401837,13248146,11648679,8650006

%N a(n) is the smallest number which can be represented as the sum of three distinct nonzero n-gonal numbers in exactly n ways, or -1 if no such number exists.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PolygonalNumber.html">Polygonal Number</a>

%e a(3) = 37 = 1 + 15 + 21 = 3 + 6 + 28 = 6 + 10 + 21.

%e a(4) = 161 = 1^2 + 4^2 + 12^2 = 2^2 + 6^2 + 11^2 = 4^2 + 8^2 + 9^2 = 5^2 + 6^2 + 10^2.

%Y Cf. A025415, A057145, A350405, A374144, A374274.

%K nonn

%O 3,1

%A _Ilya Gutkovskiy_, Jul 02 2024

%E a(21) and beyond from _Michael S. Branicky_, Jul 08 2024