A262751 The Möbius function of the poset of all permutations, ordered by pattern containment, of length at most n, with an added top element.

-1, 1, -3, 15, -97, 709, -5469, 44205, -397923, 4296945

Offset

1,3

Comments

Note that an additional top element is added to make the poset a lattice and thus allow the computation of the Möbius function.

Links

Table of n, a(n) for n=1..10.

Jason P. Smith, A formula for the Möbius function of the permutation poset based on a topological decomposition, arXiv preprint arXiv:1506.04406 [math.CO], 2015.

Jason P. Smith, Java program, 2016.

Einar Steingrimsson, Some open problems on permutation patterns, arXiv:1210.7320 [math.CO], 2012-2013.

Einar Steingrimsson, Some open problems on permutation patterns, In Surveys in Combinatorics, 409, pages 239-263. London Mathematical Society Lecture Note Series, 2013.

Crossrefs

Sequence in context: A109283 A370210 A079689 * A231445 A108442 A060148

Adjacent sequences: A262748 A262749 A262750 * A262752 A262753 A262754

Keyword

sign,hard,more

Author

Jason P Smith, Sep 30 2015

Extensions

a(10) from Jason P Smith, Jul 28 2016

Status

approved