  Consider a lattice of n sites arranged around a ring, with the $n$ sites
occupied by particles of weights $\{1,2,\dots,n\}$; the possible arrangements
of particles in sites thus corresponds to the $n!$ permutations in $S_n$. The
\emph{inhomogeneous totally asymmetric simple exclusion process} (or TASEP) is
a Markov chain on the set of permutations, in which two adjacent particles of
weights $i<j$ swap places at rate $x_i - y_{n+1-j}$ if the particle of weight
$j$ is to the right of the particle of weight $i$. (Otherwise nothing happens.)
In the case that $y_i=0$ for all $i$, the stationary distribution was
conjecturally linked to Schubert polynomials by Lam-Williams, and explicit
formulas for steady state probabilities were subsequently given in terms of
multiline queues by Ayyer-Linusson and Arita-Mallick. In the case of general
$y_i$, Cantini showed that $n$ of the $n!$ states have probabilities
proportional to double Schubert polynomials. In this paper we introduce the
class of \emph{evil-avoiding permutations}, which are the permutations avoiding
the patterns $2413, 4132, 4213$ and $3214$. We show that there are
$\frac{(2+\sqrt{2})^{n-1}+(2-\sqrt{2})^{n-1}}{2}$ evil-avoiding permutations in
$S_n$, and for each evil-avoiding permutation $w$, we give an explicit formula
for the steady state probability $\psi_w$ as a product of double Schubert
polynomials. We also show that the Schubert polynomials that arise in these
formulas are flagged Schur functions, and give a bijection in this case between
multiline queues and semistandard Young tableaux.

Combinatorics