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A211633 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>2x^2+2y^2. 2
0, 0, 0, 8, 32, 80, 160, 264, 416, 624, 864, 1176, 1552, 2000, 2528, 3144, 3856, 4640, 5552, 6584, 7712, 8960, 10352, 11880, 13520, 15328, 17296, 19416, 21712, 24176, 26832, 29640, 32672, 35904, 39312, 42968, 46816, 50896, 55184, 59736 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

For a guide to related sequences, see A211422.

LINKS

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

MATHEMATICA

t = Compile[{{u, _Integer}},

   Module[{s = 0}, (Do[If[w^2 > 2 x^2 + 2 y^2,

         s = s + 1], {w, #}, {x, #}, {y, #}] &[

      Flatten[{Reverse[-#], #} &[Range[1, u]]]]; s)]];

Map[t[#] &, Range[0, 50]]  (* A211633 *)

%/8                        (* integers *)

(* Peter J. C. Moses, Apr 13 2012 *)

CROSSREFS

Cf. A211422.

Sequence in context: A018842 A139098 A224543 * A130809 A333174 A018839

Adjacent sequences:  A211630 A211631 A211632 * A211634 A211635 A211636

KEYWORD

nonn

AUTHOR

Clark Kimberling, Apr 17 2012

STATUS

approved

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Last modified September 20 11:50 EDT 2021. Contains 347586 sequences. (Running on oeis4.)