A293651 Sum of two (possibly negative) coprime cubes in at least 3 ways, but not the sum of 2 noncoprime cubes.

3367, 68913, 152551, 195841, 625177, 684019, 1147627, 1548729, 2113921, 2628073, 2985983, 3242197, 3442887, 4488211, 4663295, 4931101, 5318677, 7194889, 8741691, 9667693, 14110579, 15072967, 15438185, 16776487, 21463407, 22910797, 24769502, 26122131, 26460217

Offset

1,1

Comments

Not every term is cubefree; some are sb^3 where s is in A159843 and b > 1.

Links

Rosalie Fay, Table of n, a(n) for n = 1..165

Example

21463407 = 271^3 + 116^3 = 284^3 - 113^3 = 368^3 - 305^3, and 271 & 116 are coprime, etc., so 21463407 is in the sequence.

Crossrefs

Cf. A023050 (positive cubes); A293650 (allows noncoprime); A293646, A293648

Sequence in context: A031556 A265625 A014441 * A212948 A204471 A139778

Adjacent sequences: A293648 A293649 A293650 * A293652 A293653 A293654

Keyword

nonn

Author

Rosalie Fay, Oct 16 2017

Status

approved