Robin J. Chapman, Timothy Y. Chow, Amit Khetan, David Petrie Moulton, Robert J. Waters. Simple formulas for lattice paths avoiding certain periodic staircase boundaries. Journal of Combinatorial Theory, Series A, 116(1):205-214, 2009. [doi]
@article{ChapmanCKMW09,
title = {Simple formulas for lattice paths avoiding certain periodic staircase boundaries},
author = {Robin J. Chapman and Timothy Y. Chow and Amit Khetan and David Petrie Moulton and Robert J. Waters},
year = {2009},
doi = {10.1016/j.jcta.2008.05.002},
url = {http://dx.doi.org/10.1016/j.jcta.2008.05.002},
researchr = {https://researchr.org/publication/ChapmanCKMW09},
cites = {0},
citedby = {0},
journal = {Journal of Combinatorial Theory, Series A},
volume = {116},
number = {1},
pages = {205-214},
}