A211649 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2=2n.

0, 0, 0, 3, 0, 0, 1, 6, 0, 3, 0, 3, 3, 6, 0, 6, 0, 3, 3, 9, 0, 6, 3, 6, 1, 6, 0, 12, 6, 0, 0, 12, 0, 12, 3, 6, 3, 12, 3, 6, 0, 3, 6, 15, 3, 12, 0, 12, 3, 12, 0, 6, 6, 6, 4, 18, 0, 12, 6, 9, 6, 12, 0, 18, 0, 0, 6, 21, 3, 12, 6, 6, 3, 21, 0, 15, 9, 12, 0, 12, 0, 12, 9, 15, 6, 12, 3, 18

Offset

0,4

Comments

For a guide to related sequences, see A211422.

Links

Table of n, a(n) for n=0..87.

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
    (Do[If[w^2 + x^2 + y^2 == 2 n, s = s + 1],
        {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 400]]    (* A211649 *)
-1 + Flatten[Position[%, 0]]  (* A182195 *)
(* Peter J. C. Moses, Apr 13 2012 *)

Crossrefs

Cf. A211422.

Sequence in context: A349911 A090030 A293616 * A202023 A080159 A144299

Adjacent sequences: A211646 A211647 A211648 * A211650 A211651 A211652

Keyword

nonn

Author

Clark Kimberling, Apr 18 2012

Status

approved