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 A179797 #5 Feb 12 2013 18:09:42
%S A179797 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,
%T A179797 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,
%U A179797 51,52,53,54,55,56,57,58,59,60,62,63,64,65,66,67,68,69,70,71,73,74,75
%N A179797 Numbers not of the form abc + abd + acd + bcd, with 0 < a < b < c < d.
%C A179797 This sequence appears to contain 764 terms, ending with 181799. Complement of A179796.
%H A179797 T. D. Noe, <a href="/A179797/b179797.txt">Table of n, a(n) for n=1..764</a> (complete sequence)
%H A179797 MathOverflow, <a href="http://mathoverflow.net/questions/33411">A generalisation of the equation n = ab + ac + bc</a>
%t A179797 nn=1000000; lim=Floor[nn^(1/3)]; cnt=Table[0,{nn}]; Do[k1=a*b*c; k2=a*b+a*c+b*c; d=0; While[d++; n=k1+k2*d; n<=nn, If[d!=a && d!=b && d!=c, cnt[[n]]=1]], {a,lim}, {b,a+1,Floor[Sqrt[nn/a]]}, {c,b+1,Floor[nn/a/b]}]; Flatten[Position[cnt,0]]
%Y A179797 Cf. A027563 (which allows equality)
%K A179797 fini,full,nonn
%O A179797 1,2
%A A179797 _T. D. Noe_, Aug 02 2010