A293648 Sum of two (possibly negative) coprime cubes in at least 2 ways, but not the sum of 2 noncoprime cubes.

91, 217, 721, 1027, 1729, 3367, 4706, 4921, 4977, 7657, 8587, 8911, 9919, 10621, 14911, 15561, 16263, 20683, 21014, 23877, 25669, 27937, 28063, 31519, 35929, 39331, 40033, 49959, 63693, 68705, 68857, 68913, 73017, 77653, 77779, 97309, 98623, 106597, 109573

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..325

Example

63693 = 34^3 + 29^3 = 53^3 - 44^3 and 34 & 29 are coprime, as are 53 & -44, but it is not also the sum of cubes of 2 noncoprime integers, so 63693 is in the sequence.

Crossrefs

Cf. A293647 (allows noncoprime); A293649 (only positives); A293646, A293651

Sequence in context: A339523 A260064 A207077 * A225909 A051973 A290812

Adjacent sequences: A293645 A293646 A293647 * A293649 A293650 A293651

Keyword

nonn

Author

Rosalie Fay, Oct 16 2017

Status

approved