A293650 Sum of two (possibly negative) cubes in at least 3 ways (primitive solutions).

728, 3367, 4104, 5859, 46683, 65728, 68913, 101528, 124488, 134379, 152551, 155736, 165464, 168112, 184464, 195841, 205352, 289224, 333944, 342657, 402597, 439101, 622232, 625177, 684019, 754299, 757701, 842751, 845208, 1009736, 1016496, 1062936, 1073375

Offset: 1

Author

Rosalie Fay, Oct 16 2017

Keywords

• nonn

Comments

Primitive means that the 6 summands are coprime. Not every term is the sum of two coprime cubes. a(1) = A047696(3).

Examples

			4104 = 18^3 - 12^3 = 16^3 + 2^3 = 15^3 + 9^3, and 18, -12, 16, 2, 15, 9 are coprime, so 4104 is in the sequence.
		

Links

• Rosalie Fay, Table of n, a(n) for n = 1..664

Crossrefs

Cf. A051383 (all solutions); A003825 (positive cubes); A293651 (only coprime); A293645, A293647