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 A026503 #5 Mar 31 2012 13:50:34 %S A026503 1,2,4,5,6,7,8,9,10,11,12,13,15,16,18,19,21,22,24,25,27,28,30,31,33, %T A026503 36,37,40,42,43,45,46,48,51,57,58,60,61,63,67,70,72,75,78,81,82,85,88, %U A026503 91,93,96,102,105,112,117,120,121,123,130,133 %N A026503 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 A026503 nonn %O A026503 1,2 %A A026503 _Clark Kimberling_ %E A026503 More terms from _Naohiro Nomoto_, Sep 15 2001