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A212142
Number of (w,x,y,z) with all terms in {1,...,n} and w >= (geometric mean of x,y,z).
2
0, 1, 9, 45, 145, 351, 729, 1345, 2307, 3702, 5650, 8271, 11736, 16174, 21774, 28719, 37210, 47457, 59703, 74170, 91116, 110796, 133498, 159525, 189246, 222880, 260835, 303465, 351103, 404109, 462969, 527992, 599664, 678387, 764656
OFFSET
0,3
COMMENTS
A212142(n)+A212141(n)=n^4. For a guide to related sequences, see A211795.
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]] (* A212142 geometric mean *)
(* Peter J. C. Moses, Apr 13 2012 *)
CROSSREFS
Cf. A211795.
Sequence in context: A289721 A060008 A212089 * A095166 A357717 A341988
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 06 2012
STATUS
approved