A211646 - OEIS

%I #5 Dec 04 2016 19:46:28

%S 0,0,1,4,10,17,20,26,35,44,54,60,75,87,96,108,120,133,145,163,178,196,

%T 202,220,238,256,278,284,308,329,347,365,383,401,428,440,467,495,504,

%U 528,549,576,594,612,645,678,690,717,735,765,790,814,853,871

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

%C For a guide to related sequences, see A211422.

%t t = Compile[{{n, _Integer}}, Module[{s = 0},

%t     (Do[If[w^2 + x^2 + y^2 < 3 n, s = s + 1],

%t         {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];

%t Map[t[#] &, Range[0, 80]]   (* A211646 *)

%t (* _Peter J. C. Moses_, Apr 13 2012 *)

%Y Cf. A211422.

%K nonn

%O 0,4

%A _Clark Kimberling_, Apr 18 2012