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%I #27 Nov 19 2023 09:00:15
%S 1,1,2,5,15,50,180,690,2792,11857,52633,243455,1170525,5837934,
%T 30151474,161021581,888001485,5051014786,29600662480,178541105770,
%U 1107321666920,7055339825171,46142654894331,309513540865544,2127744119042216,14979904453920111,107932371558460341,795363217306369817,5990768203554158167,46094392105916344968,362092868720288824992
%N Number of cyclic patterns of length n that avoid the vincular pattern 23-4-1.
%C The vincular pattern 23-4-1 requires the 2 and the 3 to be adjacent.
%C By the trivial Wilf equivalence obtained by reversing the permutations, a(n) is also the number of cyclic patterns of length n that avoid the vincular pattern 32-1-4.
%H Rupert Li, <a href="https://arxiv.org/abs/2107.12353">Vincular Pattern Avoidance on Cyclic Permutations</a>, arXiv:2107.12353 [math.CO], 2021.
%H Toufik Mansour and Mark Shattuck, <a href="https://arxiv.org/abs/2111.04211">Enumerating circular permutations avoiding the vincular pattern 23 4 1</a>, arXiv:2111.04211 [math.CO], 2021.
%H Toufik Mansour and Mark Shattuck, <a href="http://ajc.maths.uq.edu.au/pdf/83/ajc_v83_p176.pdf">On a question of Li concerning an uncounted class of circular permutations</a>, The Australasian Journal of Combinatorics, volume 83 part 1, 2022, pp. 176-195.
%Y Cf. A025242, A047970, A346660.
%K nonn
%O 0,3
%A _Rupert Li_, Aug 03 2021
%E More terms from _Vaclav Kotesovec_, Nov 09 2021, computed by Toufik Mansour and Mark Shattuck