OFFSET
0,3
COMMENTS
For a guide to related sequences, see A211422.
MATHEMATICA
t = Compile[{{u, _Integer}},
Module[{s = 0}, (Do[If[2 w^2 > x^2 + y^2,
s = s + 1], {w, #}, {x, #}, {y, #}] &[
Flatten[{Reverse[-#], #} &[Range[1, u]]]]; s)]];
Map[t[#] &, Range[0, 50]] (* A211632 *)
%/8 (* integers *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 17 2012
STATUS
approved