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 A216823 #11 Jan 26 2014 12:24:20 %S A216823 2,3,5,7,11,13,17,23,31,41,43,59,71,103,163,1381,1831,3041,4447,47057, %T A216823 47059,47137,61559,67213,138683,713863,775807,2861051,28282147, %U A216823 29133437,2259696349,3892535183,110725121051,1456230512169437 %N A216823 Prime factors of Giuga numbers A007850 with 8 or fewer prime divisors. %C A216823 See A007850 for comments, references, and links. %e A216823 30 = 2*3*5 is a Giuga number, so 2, 3, 5 are members. %Y A216823 Cf. A007850, A216824, A236434. %K A216823 nonn,fini,full %O A216823 1,1 %A A216823 _Jonathan Sondow_, Sep 17 2012