Calculate the number of faces of braid arrangement.

[Kalyalev]

Adds a function for calculating the number of k-dimensional faces of the braid arrangement A_n.

def number_of_braid_faces(n,k): 
    return sum([((-1)**(k-i))*binomial(k,i)*(i**n) for i in range(0,k+1)]) 	

CC: @sagetrac-etzanaki

Component: combinatorics

Author: gh-Kalyalev

Issue created by migration from https://trac.sagemath.org/ticket/27051

[Kalyalev]

Author: gh-Kalyalev

[embray]

comment:2

Retarging tickets optimistically to the next milestone. If you are responsible for this ticket (either its reporter or owner) and don't believe you are likely to complete this ticket before the next release (8.7) please retarget this ticket's milestone to sage-pending or sage-wishlist.

[embray]

comment:4

This ticket has no description now and there's nothing to review. Should it be closed?

[Kalyalev]

comment:6

Please close this ticket.
We will open a new ticket and upload a patch.

[embray]

comment:7

Opening a new ticket isn't really necessary since you can just repurpose this one, but okay...