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 A224293 #5 Apr 03 2013 11:56:54 %S A224293 0,0,0,0,0,2,32,322,2634,19216,130662,848284,5334332,32788726, %T A224293 198201268,1183152686,6995479542,41055940756,239560353258, %U A224293 1391435203864,8052418072728,46464481278410,267483032264168,1536914425518970,8817393642571330 %N A224293 Number of permutations of length n containing exactly 1 occurrence of 1234 and 1 occurrence of 1243. %H A224293 B. Nakamura, <a href="http://arxiv.org/abs/1301.5080">Approaches for enumerating permutations with a prescribed number of occurrences of patterns</a>, arXiv 1301.5080, 2013. %p A224293 # Programs can be obtained from author's personal website. %Y A224293 Cf. A006318, A224292. %K A224293 nonn %O A224293 1,6 %A A224293 _Brian Nakamura_, Apr 03 2013