@article{JIS_2015__18_7_a1,
     author = {O'Bryant, Kevin},
     title = {Sets of natural numbers with proscribed subsets},
     journal = {Journal of integer sequences},
     publisher = {mathdoc},
     volume = {18},
     number = {7},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2015__18_7_a1/}
}