cp's OEIS Frontend

A211637 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>x^2+y^2.

%I A211637 #11 Dec 04 2016 19:46:27
%S A211637 0,0,1,5,13,26,48,78,119,173,240,323,421,538,677,837,1020,1226,1460,
%T A211637 1723,2015,2337,2694,3084,3508,3969,4471,5016,5601,6227,6900,7619,
%U A211637 8389,9208,10078,11004,11981,13015,14105,15258,16472,17744,19083,20487,21962,23505
%N A211637 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>x^2+y^2.
%C A211637 For a guide to related sequences, see A211422.
%H A211637 Alois P. Heinz, <a href="/A211637/b211637.txt">Table of n, a(n) for n = 0..1000</a>
%p A211637 b:= proc(n) option remember; 1+floor(sqrt(n)) end:
%p A211637 a:= proc(n) local c, x, y, w;
%p A211637       c:= 0;
%p A211637       for x to n do
%p A211637         for y from x to n do
%p A211637           w:= b(x^2+y^2);
%p A211637           if w>n then break fi;
%p A211637           c:= c+ (n-w+1)*`if`(x=y, 1, 2)
%p A211637         od
%p A211637       od: c
%p A211637     end:
%p A211637 seq (a(n), n=0..50);  # _Alois P. Heinz_, May 10 2012
%t A211637 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A211637     (Do[If[w^2 > x^2 + y^2, s = s + 1],
%t A211637         {w, 1, #}, {x, 1, #}, {y, 1, #}] &[n]; s)]];
%t A211637 Map[t[#] &, Range[0, 50]]   (* A211637 *)
%t A211637 (* _Peter J. C. Moses_, Apr 13 2012 *)
%Y A211637 Cf. A211422.
%K A211637 nonn
%O A211637 0,4
%A A211637 _Clark Kimberling_, Apr 18 2012