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 A239298 #17 Jul 10 2015 18:03:44
%S A239298 1,1,4,27,255,3028,41972,647034,10760307,189317370,3478597980
%N A239298 Words of length n over the alphabet {0,...,n-1} that are 1342-avoiding.
%Y A239298 The permutation analog is A022558.
%Y A239298 Cf. A000312.
%K A239298 nonn,more
%O A239298 0,3
%A A239298 _Chad Brewbaker_, Mar 14 2014
%E A239298 a(8)-a(10) from _Giovanni Resta_, Mar 14 2014