A212057 Number of (w,x,y,z) with all terms in {1,...,n} and w<x*y*z.

0, 0, 11, 69, 231, 584, 1230, 2307, 3964, 6385, 9771, 14356, 20377, 28125, 37894, 50008, 64809, 82681, 104005, 129216, 158743, 193063, 232668, 278080, 329812, 388452, 454585, 528822, 611791, 704167, 806610, 919852, 1044607, 1181643

Offset

0,3

Comments

a(n)+A212058(n)=n^4. For a guide to related sequences, see A211795.

Links

Table of n, a(n) for n=0..33.

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]] (* A212057 *)
(* Peter J. C. Moses, Apr 13 2012 *)

Crossrefs

Cf. A211795, A061201.

Sequence in context: A038741 A292490 A169731 * A293550 A182188 A099336

Adjacent sequences: A212054 A212055 A212056 * A212058 A212059 A212060

Keyword

nonn

Author

Clark Kimberling, Apr 30 2012

Status

approved