A212097 Number of (w,x,y,z) with all terms in {1,...,n} and w^3<x^3+y^3+z^3.

0, 1, 15, 72, 221, 536, 1098, 2028, 3445, 5502, 8368, 12234, 17304, 23794, 31963, 42089, 54439, 69332, 87070, 108013, 132549, 161043, 193924, 231550, 274463, 323023, 377776, 439254, 507882, 584329, 669046, 762686, 865804, 979052

Offset

0,3

Comments

a(n)+A212100(n)=4^n. 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^3 < x^3 + y^3 + z^3, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 40]] (* A212097 *)
(* Peter J. C. Moses, Apr 13 2012 *)

Crossrefs

Cf. A211795.

Sequence in context: A168298 A126274 A241234 * A212098 A053531 A000476

Adjacent sequences: A212094 A212095 A212096 * A212098 A212099 A212100

Keyword

nonn

Author

Clark Kimberling, May 03 2012

Status

approved