A339997 Numbers that are the sum of an odd cube s and an even cube t such that 0 < s < t.

9, 65, 91, 217, 243, 341, 513, 539, 637, 855, 1001, 1027, 1125, 1343, 1729, 1755, 1853, 2071, 2457, 2745, 2771, 2869, 3059, 3087, 3473, 4075, 4097, 4123, 4221, 4439, 4825, 4941, 5427, 5833, 5859, 5957, 6175, 6293, 6561, 7163, 7471, 8001, 8027, 8029, 8125, 8343, 8729

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

65 is in the sequence since 1^3 + 4^3 = 1 + 64 = 65, where 0 < 1 < 64.

Maple

N:= 10000: # for terms <= N
S:= {seq(seq(s^3 + t^3, s = 1 .. min(t, floor((N-t^3)^(1/3))), 2), t = 2 .. floor(N^(1/3)), 2)}:
sort(convert(S, list)); # Robert Israel, Dec 30 2020

Mathematica

Table[If[Sum[Mod[i, 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/2]}] > 0, n, {}], {n, 1200}] // Flatten

Crossrefs

Cf. A010057.

Sequence in context: A038484 A043021 A076287 * A226929 A212668 A020299

Adjacent sequences: A339994 A339995 A339996 * A339998 A339999 A340000

Keyword

nonn

Author

Wesley Ivan Hurt, Dec 25 2020

Status

approved