cp's OEIS Frontend

A212056 Number of (w,x,y,z) with all terms in {1,...,n} and w*x>y*z+2.

%I A212056 #7 Dec 04 2016 19:46:29
%S A212056 0,0,1,19,80,230,521,1019,1800,2966,4593,6819,9768,13566,18353,24339,
%T A212056 31640,40478,51025,63523,78168,95230,114881,137459,163184,192374,
%U A212056 225265,262251,303568,349606,400633,457099,519280,587654,662481
%N A212056 Number of (w,x,y,z) with all terms in {1,...,n} and w*x>y*z+2.
%C A212056 a(n)+A212056(n)=n^4.  See A211795 for a guide to related sequences.
%t A212056 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212056 (Do[If[w*x > y*z + 2, s = s + 1],
%t A212056 {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
%t A212056 Map[t[#] &, Range[0, 50]] (* A212056 *)
%t A212056 (* _Peter J. C. Moses_, Apr 13 2012 *)
%Y A212056 Cf. A211795.
%K A212056 nonn
%O A212056 0,4
%A A212056 _Clark Kimberling_, Apr 29 2012