|
|
A211651
|
|
Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^3 >= x^3 + y^3.
|
|
6
|
|
|
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
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,4
|
|
COMMENTS
|
For a guide to related sequences, see A211422.
|
|
LINKS
|
|
|
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)]];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|