A211646 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2<3n.

0, 0, 1, 4, 10, 17, 20, 26, 35, 44, 54, 60, 75, 87, 96, 108, 120, 133, 145, 163, 178, 196, 202, 220, 238, 256, 278, 284, 308, 329, 347, 365, 383, 401, 428, 440, 467, 495, 504, 528, 549, 576, 594, 612, 645, 678, 690, 717, 735, 765, 790, 814, 853, 871

Offset: 0

Author

Clark Kimberling, Apr 18 2012

Keywords

• nonn

Comments

For a guide to related sequences, see A211422.

Crossrefs

Cf. A211422.

Programs

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
    (Do[If[w^2 + x^2 + y^2 < 3 n, s = s + 1],
        {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 80]]   (* A211646 *)
(* Peter J. C. Moses, Apr 13 2012 *)