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 A112409 #3 Feb 27 2009 03:00:00 %S A112409 1,2,2,3,3,4,4,5,6,4,5,6,7,10,12,8,10,12,15,8,9,12,14,15,20,8,9,12,14, %T A112409 20,21,30 %N A112409 Table read by rows: for each n: the orders of the permutations of n elements, excluding those that are a divisor of the order of another permutation of n elements. %e A112409 1: 1, 2: 2, 3: 2 3, 4: 3 4, 5: 4 5 6, 6: 4 5 6, 7: 7 10 12... %e A112409 Permutations of 7 elements have orders of 1, 2, 3, 4, 5, 6, 7, 10, 12, of which 7, 10 and 12 are not factors of any others. %Y A112409 Cf. A000793. %K A112409 easy,nonn,tabf %O A112409 1,2 %A A112409 Allen Tracht (atracht(AT)ix.netcom.com), Dec 08 2005