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 A202221 #6 Mar 30 2012 17:30:01 %S A202221 1,2,6,24,119,708,4914,38976,347790,3448212,37606536,447426144, %T A202221 5766888120,80047243080,1190459039364,18884750846976,318300264871440, %U A202221 5680496863401840,107008122578788800,2121893387875882944,44179385761361239200,963649662245743556160 %N A202221 Number of permutations avoiding the consecutive pattern 41523. %C A202221 a(n) is the number of permutations on [n] that avoid the consecutive pattern 41523. It is the same as the number of permutations which avoid 24153, 31524, 35142, 42513, 25143, 32514 or 34152. %H A202221 Ray Chandler, <a href="/A202221/b202221.txt">Table of n, a(n) for n = 1..40</a> %H A202221 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 A202221 Cf. A177523, A202213-A202236. %K A202221 nonn %O A202221 1,2 %A A202221 _Ray Chandler_, Dec 15 2011