Entry P0006
ID: P0006
Patterns: 3 2 1
3 4 1 2
Title: Boolean principal order ideals in the Bruhat order
Permutations whose reduced decompositions contain no repeated letters
Permutations for which length equals reflection length
Unimodal permutations
Parking outcomes (of n cars in n spots) for which all cars have preference independence under the MVP parking rule
The Schubert variety X(w) is toric
References: B.E. Tenner, Pattern avoidance and the Bruhat order, J. Combin. Theory Ser. A 114 (2007), 888-905.
T.K. Petersen and B.E. Tenner, The depth of a permutation, J. Combin. 6 (2015), 145-178
P.E. Harris, B.M. Kamau, J.C. Martinez Mori, and R. Tian, On the outcome map of MVP parking functions: permutations avoiding 321 and 3412, and Motzkin paths, arXiv:2207.13041
P. Karuppuchany, On Schubert varieties, Commun. Algebra 41 (2013), 1365-1368.
Enumeration: Alternating Fibonacci numbers: F(2n - 1)
OEIS: A001519
A105306
Contributor: Bridget Tenner - November 13, 2005
Pamela Harris - August 2, 2022