A134738 Cubes which are not the sum of three squares.

343, 3375, 12167, 21952, 29791, 59319, 103823, 166375, 216000, 250047, 357911, 493039, 658503, 778688, 857375, 1092727, 1367631, 1404928, 1685159, 1906624, 2048383, 2460375, 2924207, 3442951, 3796416, 4019679, 4657463, 5359375

Offset

1,1

Comments

This sequence was inspired by e-mail from Ray Chandler, Nov 07 2007

Links

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

Formula

a(n) = A004215(n)^3. [From Ray Chandler, Jan 29 2009]

Maple

N:= 10^10: # to get all terms <= N
sort([seq(seq(4^(3*i) * (8*j + 7)^3, j = 0 .. floor((N^(1/3)/4^i - 7)/8)), i = 0 .. floor(log[4](N^(1/3))))]); # Robert Israel, Dec 26 2017

Mathematica

b = Table[x^3, {x, 1, 300}]; a = {}; Do[Do[Do[AppendTo[a, (x^2 + y^2 + z^2)^3], {x, 0, 30}], {y, 0, 30}], {z, 0, 30}]; Union[a]; Complement[b, a] (*Artur Jasinski*)
Select[Range[200]^3, SquaresR[3, #]==0&] (* Harvey P. Dale, Feb 03 2015 *)

Crossrefs

Cf. A004215, A134739.

Sequence in context: A016923 A016983 A267321 * A017151 A017247 A017355

Adjacent sequences: A134735 A134736 A134737 * A134739 A134740 A134741

Keyword

nonn

Author

Artur Jasinski, Nov 07 2007

Extensions

Extended by Ray Chandler, Jan 29 2009

Status

approved