A374809 a(n) is the smallest number which can be represented as the sum of 4 distinct nonzero tetrahedral numbers in exactly n ways, or -1 if no such number exists.

35, 115, 260, 315, 760, 705, 1310, 1824, 2365, 1915, 2475, 3335, 6240, 4645, 7735, 8455, 12120, 11505, 15440, 13026, 17325, 20020, 24125, 25575, 26400, 32935, 34440, 36575, 40040, 37180, 44265, 50400, 55100, 60060, 56560, 59160, 60620

Offset: 1

Author

Ilya Gutkovskiy, Jul 20 2024

Keywords

• nonn

Examples

			a(3) = 260 = 1 + 4 + 35 + 220 = 1 + 10 + 84 + 165 = 4 + 35 + 56 + 165.
		

Links

• Eric Weisstein's World of Mathematics, Tetrahedral Number

Crossrefs

Cf. A000292, A334013, A374807, A374808.