A374806 a(n) is the smallest number which can be represented as the sum of 3 distinct nonzero triangular numbers in exactly n ways, or -1 if no such number exists.

10, 19, 37, 52, 82, 109, 136, 241, 226, 217, 247, 364, 427, 457, 541, 532, 577, 637, 961, 721, 787, 1066, 1102, 1381, 1267, 1564, 1192, 1396, 1816, 1501, 1612, 1927, 1942, 2242, 1792, 2842, 2587, 2557, 2422, 2866, 2887, 3181, 3271, 3412, 4126

Offset: 1

Author

Ilya Gutkovskiy, Jul 20 2024

Keywords

• nonn

Examples

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

Links

• Eric Weisstein's World of Mathematics, Triangular Number

Crossrefs

Cf. A000217, A025415, A342326, A374807.