A212144 Number of (w,x,y,z) with all terms in {1,...,n} and w > (geometric mean of x,y,z).

0, 0, 7, 42, 135, 340, 717, 1332, 2281, 3657, 5604, 8224, 11676, 16113, 21712, 28656, 37122, 47368, 59583, 74049, 90988, 110667, 133368, 159394, 189084, 222681, 260635, 303210, 350841, 403846, 462705, 527727, 599332, 678054, 764322

Offset

0,3

Comments

A212144(n)+A212143(n)=n^4. For a guide to related sequences, see A211795.

Links

Table of n, a(n) for n=0..34.

Mathematica

t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w^3 > x*y*z, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 50]] (* A212144 *)
(* Peter J. C. Moses, Apr 13 2012 *)

Crossrefs

Cf. A211795.

Sequence in context: A044109 A195320 A110451 * A266387 A008526 A057425

Adjacent sequences: A212141 A212142 A212143 * A212145 A212146 A212147

Keyword

nonn

Author

Clark Kimberling, May 06 2012

Status

approved