A211651 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^3 >= x^3 + y^3.

0, 0, 1, 5, 14, 29, 53, 88, 134, 195, 270, 362, 473, 605, 762, 941, 1147, 1380, 1644, 1941, 2268, 2632, 3031, 3471, 3948, 4471, 5037, 5646, 6306, 7011, 7770, 8582, 9447, 10369, 11347, 12388, 13490, 14653, 15883, 17179, 18542, 19980, 21487

Offset: 0

Author

Clark Kimberling, Apr 19 2012

Keywords

• nonn

Comments

For a guide to related sequences, see A211422.

Links

• Robert Israel, Table of n, a(n) for n = 0..2000

Crossrefs

Cf. A211422.

Programs

Maple

g:= proc(n) local  x;
  add(floor((n^3-x^3)^(1/3)),x=1..n-1)
end proc:
ListTools:-PartialSums(map(g, [$0..50])); # Robert Israel, May 03 2019

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
    (Do[If[w^3 >= x^3 + y^3, s = s + 1],
        {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
Map[t, Range[0, 50]]  (* A211651 *)
(* Peter J. C. Moses, Apr 13 2012 *)