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A022556 Numbers that are a sum of a square and 2 nonnegative cubes. 2
0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 16, 17, 18, 20, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 43, 44, 45, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 65, 66, 68, 69, 70, 71, 72, 73, 74, 76, 77, 79, 80, 81, 82, 83, 84, 88, 89, 90, 91, 92, 95, 97, 99, 100 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Jean-François Alcover, Table of n, a(n) for n = 1..39986
MAPLE
isA022556 := proc(n)
local a2, b, c ;
for b from 0 do
if b^3 > n then
return false;
end if;
for c from b do
a2 := n-b^3-c^3 ;
if a2 < 0 then
break;
end if;
if issqr(a2) then
return true;
end if;
end do:
end do:
end proc: # R. J. Mathar, Sep 02 2016
MATHEMATICA
smax = 50000;
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 (* Jean-François Alcover, Feb 17 2023 *)
CROSSREFS
Cf. A022557 (complement).
Sequence in context: A032854 A031992 A023749 * A250482 A172233 A189891
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Jean-François Alcover, Apr 07 2020
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)