A212066 Number of (w,x,y,z) with all terms in {1,...,n} and w^2>x*y*z.

0, 0, 4, 24, 71, 166, 322, 571, 928, 1403, 2043, 2875, 3906, 5183, 6727, 8584, 10762, 13303, 16219, 19601, 23442, 27766, 32636, 38080, 44130, 50771, 58147, 66243, 75099, 84768, 95238, 106629, 118939, 132179, 146448, 161761, 178106

Offset: 0

Author

Clark Kimberling, Apr 30 2012

Keywords

• nonn

Comments

a(n)+A212065(n)=n^4. For a guide to related sequences, see A211795.

Crossrefs

Cf. A211795.

Programs

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w^2 > x*y*z, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 50]] (* A212066 *)
(* Peter J. C. Moses, Apr 13 2012 *)