Anders Claesson, Toufik Mansour. Counting occurrences of a pattern of type (1, 2) or (2, 1) in permutations. Adv. Appl. Math., 29(2):293-310, 2002. [doi]
@article{ClaessonM02,
title = {Counting occurrences of a pattern of type (1, 2) or (2, 1) in permutations},
author = {Anders Claesson and Toufik Mansour},
year = {2002},
doi = {10.1016/S0196-8858(02)00012-X},
url = {https://doi.org/10.1016/S0196-8858(02)00012-X},
researchr = {https://researchr.org/publication/ClaessonM02},
cites = {0},
citedby = {0},
journal = {Adv. Appl. Math.},
volume = {29},
number = {2},
pages = {293-310},
}