A297931 Numbers that are not the sum of a square and 3 nonnegative cubes.

15, 22, 23, 48, 86, 94, 112, 120, 139, 184, 203, 211, 230, 237, 263, 301, 309, 312, 335, 373, 399, 1014, 1056, 1455, 1644, 2029, 2272, 2658, 3309, 3469, 4019, 6502, 11101

Offset

1,1

Comments

After 11101, there are no more terms up to 570000.

No more terms < 10^10; is this sequence finite? - Mauro Fiorentini, Jan 26 2019

Links

Table of n, a(n) for n=1..33.

Eric Weisstein's World of Mathematics, Waring's Problem

Mathematica

t1={};
Do[Do[If[x^2+y^2+z^2+w^3==n, AppendTo[t1, n]&&Break[]], {x, 0, n^(1/2)}, {y, x, (n-x^2)^(1/2)}, {z, y, (n-x^2-y^2)^(1/2)}, {w, 0, (n-x^2-y^2-z^2)^(1/3)}], {n, 0, 5.7*10^5}];
t2={};
Do[If[FreeQ[t1, k]==True, AppendTo[t2, k]], {k, 0, 5.7*10^5}];
t2

Crossrefs

Cf. A004215, A022552, A022557, A022561, A022566, A111151.

Sequence in context: A300958 A066758 A338119 * A018888 A115174 A092783

Adjacent sequences: A297928 A297929 A297930 * A297932 A297933 A297934

Keyword

nonn

Author

XU Pingya, Jan 08 2018

Status

approved