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A211642 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2+x^2+y^2<2n. 2
0, 0, 1, 1, 4, 7, 10, 11, 17, 20, 26, 32, 35, 38, 48, 54, 60, 66, 75, 78, 87, 96, 105, 114, 120, 127, 139, 145, 157, 169, 178, 184, 196, 202, 217, 232, 238, 244, 263, 278, 284, 296, 308, 314, 329, 347, 365, 371, 383, 389, 410, 428, 434, 452, 467, 477 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

For a guide to related sequences, see A211422.

LINKS

Table of n, a(n) for n=0..55.

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, 80]]     (* A211642 *)

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

CROSSREFS

Cf. A211422.

Sequence in context: A190507 A087298 A237707 * A127958 A000414 A025357

Adjacent sequences:  A211639 A211640 A211641 * A211643 A211644 A211645

KEYWORD

nonn

AUTHOR

Clark Kimberling, Apr 18 2012

STATUS

approved

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Last modified July 5 21:00 EDT 2020. Contains 335473 sequences. (Running on oeis4.)