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A211649 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2=2n. 3

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

%S 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,

%T 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,

%U 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

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

%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 == 2 n, s = s + 1],

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

%t Map[t[#] &, Range[0, 400]] (* A211649 *)

%t -1 + Flatten[Position[%, 0]] (* A182195 *)

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

%Y Cf. A211422.

%K nonn

%O 0,4

%A _Clark Kimberling_, Apr 18 2012

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Last modified August 24 16:25 EDT 2024. Contains 375417 sequences. (Running on oeis4.)