A022557 Numbers that are not the sum of a square and 2 nonnegative cubes.

7, 14, 15, 19, 21, 22, 23, 30, 40, 42, 46, 47, 48, 56, 59, 61, 62, 67, 75, 78, 85, 86, 87, 93, 94, 96, 98, 104, 105, 106, 110, 111, 112, 115, 117, 119, 120, 124, 131, 138, 139, 143, 147, 157, 159, 163, 166, 167, 173, 176, 180, 181, 183, 184, 187, 194, 195, 199, 200, 202

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Links

• R. J. Mathar, Table of n, a(n) for n = 1..9477

Crossrefs

Cf. A022556 (complement).

Programs

Maple

isA022557 := proc(n)
    not isA022556(n) ;
end proc:
n := 1:
for c from 0 do
    if isA022557(c) then
        printf("%d %d\n",n,c);
        n := n+1 ;
    end if;
end do: # R. J. Mathar, Sep 02 2016

Mathematica

smax = 50000;
A022556 = Table[s = i^2 + j^3 + k^3; If[s <= smax, s, Nothing], {i, 0, Sqrt[smax] // Ceiling}, {j, 0, smax^(1/3) // Ceiling}, {k, j, smax^(1/3) // Ceiling}] // Flatten // Union;
Complement[Range[smax], A022556] (* Jean-François Alcover, Feb 20 2023 *)