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A212056
Number of (w,x,y,z) with all terms in {1,...,n} and w*x>y*z+2.
3
0, 0, 1, 19, 80, 230, 521, 1019, 1800, 2966, 4593, 6819, 9768, 13566, 18353, 24339, 31640, 40478, 51025, 63523, 78168, 95230, 114881, 137459, 163184, 192374, 225265, 262251, 303568, 349606, 400633, 457099, 519280, 587654, 662481
OFFSET
0,4
COMMENTS
a(n)+A212056(n)=n^4. See A211795 for a guide to related sequences.
MATHEMATICA
t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[w*x > y*z + 2, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 50]] (* A212056 *)
(* Peter J. C. Moses, Apr 13 2012 *)
CROSSREFS
Cf. A211795.
Sequence in context: A050522 A366965 A172973 * A290224 A071633 A334086
KEYWORD
nonn
AUTHOR
Clark Kimberling, Apr 29 2012
STATUS
approved