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A212141
Number of (w,x,y,z) with all terms in {1,...,n} and w < (geometric mean of x,y,z).
2
0, 0, 7, 36, 111, 274, 567, 1056, 1789, 2859, 4350, 6370, 9000, 12387, 16642, 21906, 28326, 36064, 45273, 56151, 68884, 83685, 100758, 120316, 142530, 167745, 196141, 227976, 263553, 303172, 347031, 395529, 448912, 507534, 571680
OFFSET
0,3
COMMENTS
A212141(n)+A212142(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]] (* A212141 *)
(* Peter J. C. Moses, Apr 13 2012 *)
CROSSREFS
Cf. A211795.
Sequence in context: A163683 A103090 A250414 * A212088 A184246 A097554
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 06 2012
STATUS
approved