A211641 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2>=n.

0, 1, 8, 27, 63, 124, 215, 339, 508, 725, 993, 1324, 1718, 2186, 2733, 3358, 4079, 4896, 5812, 6836, 7974, 9235, 10616, 12132, 13789, 15587, 17538, 19639, 21904, 24341, 26946, 29731, 32708, 35877, 39238, 42806, 46581, 50575, 54794, 59232

Offset

0,3

Comments

For a guide to related sequences, see A211422.

Links

Table of n, a(n) for n=0..39.

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
    (Do[If[w^2 + x^2 + y^2 >= n, s = s + 1],
        {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 80]]     (* A211641 *)
(* Peter J. C. Moses, Apr 13 2012 *)

Crossrefs

Cf. A211422.

Sequence in context: A224134 A213488 A151675 * A062686 A093322 A017670

Adjacent sequences: A211638 A211639 A211640 * A211642 A211643 A211644

Keyword

nonn

Author

Clark Kimberling, Apr 18 2012

Status

approved