{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T11:33:30Z","timestamp":1760441610739,"version":"3.41.2"},"reference-count":0,"publisher":"The Electronic Journal of Combinatorics","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Electron. J. Combin."],"abstract":"<jats:p>The obstacle number is a new graph parameter introduced by Alpert, Koch,\u00a0and Laison (2010). Mukkamala et al. (2012) show that there exist graphs\u00a0with $n$ vertices having obstacle number in $\\Omega(n\/\\log n)$. In this\u00a0note, we up this lower bound to $\\Omega(n\/(\\log\\log n)^2)$. Our proof\u00a0makes use of an upper bound of Mukkamala et al. on the number of graphs\u00a0having obstacle number at most $h$ in such a way that any subsequent\u00a0improvements to their upper bound will improve our lower bound.<\/jats:p>","DOI":"10.37236\/4373","type":"journal-article","created":{"date-parts":[[2020,1,10]],"date-time":"2020-01-10T23:34:58Z","timestamp":1578699298000},"source":"Crossref","is-referenced-by-count":8,"title":["On Obstacle Numbers"],"prefix":"10.37236","volume":"22","author":[{"given":"Vida","family":"Dujmovi\u0107","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pat","family":"Morin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"23455","published-online":{"date-parts":[[2015,7,1]]},"container-title":["The Electronic Journal of Combinatorics"],"original-title":[],"link":[{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/download\/v22i3p1\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/download\/v22i3p1\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,1,17]],"date-time":"2020-01-17T10:14:39Z","timestamp":1579256079000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.combinatorics.org\/ojs\/index.php\/eljc\/article\/view\/v22i3p1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,7,1]]},"references-count":0,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2015,7,1]]}},"URL":"https:\/\/doi.org\/10.37236\/4373","relation":{},"ISSN":["1077-8926"],"issn-type":[{"type":"electronic","value":"1077-8926"}],"subject":[],"published":{"date-parts":[[2015,7,1]]},"article-number":"P3.1"}}