OFFSET
0,3
FORMULA
a(n) = Sum_{i=1..n+1} Sum_{j=1..n+1} tau(i)*floor((n+1-j)/i). - Ridouane Oudra, Oct 03 2020
MATHEMATICA
t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w >= x*y*z, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 50]] (* A212058 *)
(* Peter J. C. Moses, Apr 13 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 30 2012
STATUS
approved