login
A339994
Sums of two distinct nonzero even cubes.
0
72, 224, 280, 520, 576, 728, 1008, 1064, 1216, 1512, 1736, 1792, 1944, 2240, 2728, 2752, 2808, 2960, 3256, 3744, 4104, 4160, 4312, 4472, 4608, 5096, 5824, 5840, 5896, 6048, 6344, 6832, 6840, 7560, 8008, 8064, 8216, 8512, 8576, 9000, 9728, 9928, 10656, 10712, 10744
OFFSET
1,1
FORMULA
a(n) = 8 * A024670(n). - Rémy Sigrist, Jun 06 2021
EXAMPLE
224 is in the sequence since 2^3 + 6^3 = 8 + 216 = 224, where 8 and 216 are even cubes such 0 < 8 < 216.
MATHEMATICA
Table[If[Sum[Mod[i + 1, 2] Mod[n - i + 1, 2] (Floor[i^(1/3)] - Floor[(i - 1)^(1/3)]) (Floor[(n - i)^(1/3)] - Floor[(n - i - 1)^(1/3)]), {i, Floor[(n - 1)/2]}] > 0, n, {}], {n, 1200}] // Flatten
Total/@Subsets[Range[2, 22, 2]^3, {2}]//Union (* Harvey P. Dale, Sep 18 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Dec 25 2020
STATUS
approved