A335658 Numbers that are not the sum of 3 nonzero squares and a positive cube.

0, 1, 2, 3, 5, 6, 8, 9, 16, 21, 24, 40

Offset: 1

Author

XU Pingya, Jun 17 2020

Keywords

• nonn
• more

Comments

No more terms up to 6*10^5.

Crossrefs

Cf. A000534, A004214, A297788.

Programs

Mathematica

n = 5 * 10^4.;
t = Union@Flatten@Table[x^2 + y^2 + z^2 + w^3, {x,(n/3)^(1/2)}, {y,x,((n-x^2)/2)^(1/2)},{z,y,(n-x^2-y^2)^(1/2)}, {w,(n-x^2-y^2-z^2)^(1/3)}];
Complement[Range[0,n],t]