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A211921
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Number of (w,x,y,z) with all terms in {1,...,n} and 2w*x<=3*y*z.
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3
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0, 1, 11, 58, 176, 407, 840, 1536, 2591, 4133, 6268, 9119, 12895, 17684, 23706, 31201, 40315, 51239, 64352, 79770, 97829, 118795, 142947, 170548, 202114, 237757, 277915, 323080, 373489, 429449, 491670, 560274, 635851, 718858, 809692
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OFFSET
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0,3
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COMMENTS
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See A211795 for a guide to related sequences.
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LINKS
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MATHEMATICA
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t = Compile[{{n, _Integer}}, Module[{s = 0},
(Do[If[2 w*x <= 3 y*z, s = s + 1],
{w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
Map[t[#] &, Range[0, 40]] (* A211921 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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