A383433 Number of king permutations on n elements avoiding the mesh pattern (12, {(0,0),(0,2),(1,0),(1,2),(2,1)}).
1, 1, 0, 0, 2, 12, 76, 556, 4592, 42328, 431184, 4812936, 58440200, 767098296, 10826066776, 163496360680, 2631146363384, 44953977477160, 812713132751832, 15501004918724712, 311078390317974872, 6552553451281418472, 144550752700158416920, 3332886257051337065128, 80168754370190239256408
Offset: 0
A383434 Number of king permutations on n elements avoiding the mesh pattern (12, {(0,2),(1,0),(1,1),(2,0),(2,1)}).
1, 1, 0, 0, 2, 10, 68, 500, 4170, 38730, 397172, 4459116, 54421082, 717571442, 10167743668, 154104395348, 2487968793386, 42630767594522, 772730550801940, 14773475294401180, 297121458577213850, 6270996358146824738, 138591948457411817684, 3200867594024256790020, 77112844928711640695594
Offset: 0
Comments
A permutation p(1)p(2)...p(n) is a king permutation if |p(i+1)-p(i)|>1 for each 0
Examples
For n = 4 the a(4) = 2 solutions are the two permutations 2413 and 3142. For n = 5 the a(5) = 10 solutions are these 10 permutations: 24153, 25314, 31524, 35142, 35241, 41352, 42513, 42531, 52413, 53142.
Links
- Dan Li and Philip B. Zhang, Distributions of mesh patterns of short lengths on king permutations, arXiv:2411.18131 [math.CO], 2024. See Theorem 4.8 at page 23.
Crossrefs
Formula
G.f.: 1 + t + 1/(1 + t) - 1/A(t) where A(t)=Sum_{n >= 0} n!*t^n*(1-t)^n/(1+t)^n is the g.f. for king permutations given by A002464.
Comments
Examples
Links
Crossrefs
Formula