Ulrich Tamm. Size of Downsets in the Pushing Order and a Problem of Berlekamp. Electronic Notes in Discrete Mathematics, 21:373-376, 2005. [doi]
@article{Tamm05,
title = {Size of Downsets in the Pushing Order and a Problem of Berlekamp},
author = {Ulrich Tamm},
year = {2005},
doi = {10.1016/j.endm.2005.07.058},
url = {http://dx.doi.org/10.1016/j.endm.2005.07.058},
researchr = {https://researchr.org/publication/Tamm05},
cites = {0},
citedby = {0},
journal = {Electronic Notes in Discrete Mathematics},
volume = {21},
pages = {373-376},
}