A014440 Differences between two positive cubes in exactly 2 ways.

721, 728, 999, 5768, 5824, 5859, 7992, 8911, 9919, 10621, 12663, 12824, 19467, 19656, 23877, 25669, 26973, 27937, 28063, 34209, 35208, 35929, 41743, 43561, 46144, 46592, 46872, 49959, 53144, 63936, 68857, 68913, 71288, 77779, 79352, 80379, 84968, 90125

Offset: 1

Author

Glen Burch (gburch(AT)erols.com)

Keywords

• nonn

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000578, A181123, A014439 (exactly one way), A034179 (more than one way), A265625 (more than two ways), A014441 (exactly three ways), A333376, A333377.

Programs

Mathematica

r = 90125; p = 3; Sort@Drop[Flatten@Select[Tally@Reap[Do[n = i^p - j^p; If[n <= r, Sow[n]], {i, Ceiling[(r/p)^(1/(p - 1))]}, {j, i}]][[2, 1]], #[[2]] == 2 &], {2, -1, 2}] (* Arkadiusz Wesolowski, Dec 10 2015 *)

Extensions

Extended by Don Reble, Nov 19 2006