@article{JIS_2003__6_1_a0,
     author = {Speed,  Sam E.},
     title = {The integer sequence {A002620} and upper antagonistic functions},
     journal = {Journal of integer sequences},
     year = {2003},
     volume = {6},
     number = {1},
     zbl = {1012.05009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2003__6_1_a0/}
}