Dun, Q., Remmel, J.B., Sergel, E. and Xin, G. 2018. On the Schur Positivity of $\Delta_{e_2} e_n[X]$. The Electronic Journal of Combinatorics. 25, 4 (Oct. 2018), P4.20. DOI:https://doi.org/10.37236/7494.