This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A067753 #12 Aug 09 2025 07:34:28
%S A067753 3,6,7,6,9,12,9,9,9,12,15,12,9,18,18,9,15,12,15,18,18,12,21,18,9,24,
%T A067753 15,12,21,24,21,15,18,18,30,18,9,24,30,18,27,24,15,24,18,18,33,18,15,
%U A067753 24,30,18,21,24,30,30,18,12,39,24,21,30,30,15,30,36,15,30,30,24,45,18,15,36
%N A067753 Number of primitive solutions in nonnegative integers of x*y+x*z+y*z = n.
%C A067753 An upper bound on the number of solutions appears to be 9*sqrt(n). - _T. D. Noe_, Jun 14 2006
%H A067753 T. D. Noe, <a href="/A067753/b067753.txt">Table of n, a(n) for n = 1..10000</a>
%e A067753 a(9)=9 because of permutations of (0,1,9) and (1,1,4) (but not (0,3,3)).
%t A067753 CntFunc[s_List] := Module[{len=Length[Union[s]]}, If[len==3,6,If[len==2,3,1]]]; Table[cnt=0; Do[z=(n-x*y)/(x+y); If[IntegerQ[z] && GCD[x,y,z]==1, cnt=cnt+CntFunc[{x,y,z}]], {x,0,Sqrt[n/3]}, {y, Max[1,x],Sqrt[x^2+n]-x}]; cnt, {n,100}] (* _T. D. Noe_, Jun 14 2006 *)
%Y A067753 Cf. A066751, A067752, A067754.
%K A067753 easy,nonn
%O A067753 1,1
%A A067753 _Colin Mallows_, Jan 31 2002
%E A067753 Corrected and extended by _T. D. Noe_, Jun 14 2006