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 A026502 #4 Mar 30 2012 18:56:08 %S A026502 1,2,3,4,6,10,17,18,22,23,25,29,30,31,38,39,41,42,46,49,50,52,55,57, %T A026502 58,62,65,66,67,70 %N A026502 a(n) = least positive integer > a(n-1) and not a(j)*a(k) + a(k)*a(i) + a(i)*a(j) for 1<=i<=j<=k<=n. %K A026502 nonn %O A026502 1,2 %A A026502 _Clark Kimberling_