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Number of permutations avoiding the consecutive pattern 45231.
1

%I #6 Mar 30 2012 17:30:04

%S 1,2,6,24,119,708,4915,38992,347980,3450572,37637545,447857256,

%T 5773243451,80146549212,1192100892680,18913413488544,318827489139059,

%U 5690693361661052,107215038571876213,2126290615269312536,44277066284532913066,965913951460006237612

%N Number of permutations avoiding the consecutive pattern 45231.

%C a(n) is the number of permutations on [n] that avoid the consecutive pattern 45231. It is the same as the number of permutations which avoid 13254, 21435 or 53412.

%H Ray Chandler, <a href="/A202233/b202233.txt">Table of n, a(n) for n = 1..40</a>

%H 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 Cf. A177523, A202213-A202236.

%K nonn

%O 1,2

%A _Ray Chandler_, Dec 15 2011