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 A060249 #11 Oct 12 2015 18:11:05 %S A060249 1,1,6,24,120,1440,5040,40320,362880,3628800,39916800,479001600, %T A060249 6227020800,87178291200,1307674368000,20922789888000,355687428096000, %U A060249 6402373705728000,121645100408832000,2432902008176640000 %N A060249 Size of the automorphism group of the symmetric group S_n. %C A060249 For all n except n=2 and n=6, Aut(S_n) is S_n itself, i.e. S_n has no outer automorphisms. Aut(S_2) is trivial and Aut(S_6) is of order 2*|S_6| = 1440 - there is an outer involution. %F A060249 a(n) = n! except for n=2 and 6. %o A060249 (PARI) if(n>6,n!,[1, 1, 6, 24, 120, 1440][n]) \\ _Charles R Greathouse IV_, Oct 12 2015 %Y A060249 Cf. A000142. %K A060249 nonn,easy %O A060249 1,3 %A A060249 Ola Veshta (olaveshta(AT)my-deja.com), Mar 22 2001 %E A060249 Offset corrected by _Stephen A. Silver_, Feb 09 2013