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A211636
Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>=x^2+y^2.
4
0, 0, 1, 5, 13, 28, 50, 80, 121, 175, 244, 327, 425, 544, 683, 845, 1028, 1236, 1470, 1733, 2027, 2349, 2706, 3096, 3520, 3985, 4489, 5034, 5619, 6247, 6922, 7641, 8411, 9230, 10102, 11030, 12007, 13043, 14133, 15288, 16504, 17778, 19117
OFFSET
0,4
COMMENTS
For a guide to related sequences, see A211422.
LINKS
MATHEMATICA
t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w^2 >= x^2 + y^2, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 50]] (* A211636 *)
(* Peter J. C. Moses, Apr 13 2012 *)
PROG
(PARI) a(n) = sum(j=0, n, sum(k=1, j-1, sqrtint(j^2-k^2))); \\ Seiichi Manyama, Oct 28 2023
CROSSREFS
Sequence in context: A344521 A316537 A175254 * A294172 A055328 A027962
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 18 2012
STATUS
approved