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A212053 Number of (w,x,y,z) with all terms in {1,...,n} and w*x<=y*z+1.

%I A212053 #8 Dec 04 2016 19:46:29
%S A212053 0,1,13,56,158,365,725,1312,2198,3477,5245,7624,10742,14725,19725,
%T A212053 25920,33470,42557,53397,66176,81150,98525,118533,141456,167606,
%U A212053 197189,230509,267920,309726,356205,407805,464744,527494,596389,671789
%N A212053 Number of (w,x,y,z) with all terms in {1,...,n} and w*x<=y*z+1.
%C A212053 a(n)+A212054(n)=n^4.  See A211795 for a guide to related sequences.
%t A212053 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212053 (Do[If[w*x <= y*z + 1, s = s + 1],
%t A212053 {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
%t A212053 Map[t[#] &, Range[0, 50]] (* A212053 *)
%t A212053 (* _Peter J. C. Moses_, Apr 13 2012 *)
%Y A212053 Cf. A211795.
%K A212053 nonn
%O A212053 0,3
%A A212053 _Clark Kimberling_, Apr 29 2012