The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A335793 Number of hare pop-stack sortable Cayley permutations. 0
 1, 1, 3, 11, 41, 151, 553, 2023, 7401 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Also, the set of Cayley permutations avoiding 231, 312, and 2121. LINKS Table of n, a(n) for n=0..8. Giulio Cerbai, Sorting Cayley permutations with pattern-avoiding machines, arXiv:2003.02536 [math.CO], 2020. See p. 16. FORMULA Conjectures from Colin Barker, Jun 24 2020: (Start) G.f.: (1 - 4*x + 4*x^2 - 2*x^3) / (1 - 5*x + 6*x^2 - 4*x^3). a(n) = 5*a(n-1) - 6*a(n-2) + 4*a(n-3) for n>3. (End) CROSSREFS Cf. A000670, A226316. Sequence in context: A086972 A218348 A320827 * A077831 A032952 A001835 Adjacent sequences: A335790 A335791 A335792 * A335794 A335795 A335796 KEYWORD nonn,more AUTHOR Michael De Vlieger, Jun 23 2020 EXTENSIONS a(7)-a(8) from Giulio Cerbai via Michael De Vlieger, Jun 24 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 22 06:24 EDT 2024. Contains 372743 sequences. (Running on oeis4.)