A211643 - OEIS

A211643

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

0, 0, 1, 4, 4, 7, 11, 17, 17, 23, 26, 35, 38, 44, 48, 60, 60, 69, 78, 87, 87, 102, 108, 120, 121, 133, 139, 157, 163, 169, 178, 196, 196, 214, 220, 238, 241, 256, 266, 284, 284, 299, 314, 329, 332, 359, 365, 383, 386, 401, 410, 434, 440, 458, 471, 495

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OFFSET

0,4

COMMENTS

Is A211643 a subsequence of A211639?

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)]];