OFFSET
0,4
COMMENTS
For a guide to related sequences, see A211422.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
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
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 18 2012
STATUS
approved