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 A211919 Number of (w,x,y,z) with all terms in {1,...,n} and w*x>=3*y*z. 3
 0, 0, 1, 14, 46, 118, 267, 497, 871, 1438, 2215, 3273, 4713, 6526, 8844, 11758, 15303, 19590, 24796, 30862, 38053, 46457, 56115, 67206, 79971, 94357, 110628, 128979, 149481, 172291, 197776, 225789, 256763, 290878, 328179, 369011 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS a(n)+A211920(n)=n^4. See A211795 for a guide to related sequences. LINKS MATHEMATICA t = Compile[{{n, _Integer}}, Module[{s = 0}, (Do[If[w*x >= 3 y*z, s = s + 1], {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]]; Map[t[#] &, Range[0, 40]] (* A211919 *) (* Peter J. C. Moses, Apr 13 2012 *) CROSSREFS Cf. A211795. Sequence in context: A043191 A043971 A233367 * A233361 A243039 A243385 Adjacent sequences:  A211916 A211917 A211918 * A211920 A211921 A211922 KEYWORD nonn AUTHOR Clark Kimberling, Apr 28 2012 STATUS approved

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Last modified February 26 18:29 EST 2020. Contains 332293 sequences. (Running on oeis4.)