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
Keywords
Links
- R. J. Mathar, Table of n, a(n) for n = 1..9477
Crossrefs
Cf. A022556 (complement).
Programs
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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
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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 *)