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 A202231 #6 Mar 30 2012 17:30:04 %S A202231 1,2,6,24,119,708,4914,38980,347862,3449292,37622348,447662376, %T A202231 5770553184,80106726784,1191471740436,18902847341664,318639524995160, %U A202231 5687162644422552,107145206713313556,2124840033683212648,44245492380155416392,965195327390976439656 %N A202231 Number of permutations avoiding the consecutive pattern 45123. %C A202231 a(n) is the number of permutations on [n] that avoid the consecutive pattern 45123. It is the same as the number of permutations which avoid 21543, 32154 or 34512. %H A202231 Ray Chandler, <a href="/A202231/b202231.txt">Table of n, a(n) for n = 1..40</a> %H A202231 A. Baxter, B. Nakamura, and D. Zeilberger. <a href="http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/auto.html">Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes</a> %Y A202231 Cf. A177523, A202213-A202236. %K A202231 nonn %O A202231 1,2 %A A202231 _Ray Chandler_, Dec 15 2011