My grandfather is Swedish, am I eligible for Swedish citizenship as an American?

I know some countries are very lenient on giving foreigners citizenship if they have some sort of direct lineage to the country in question. My mother is Korean, so I was able to get a F-4 Visa, which basically grants me Korean citizenship. Although my father is American, his father emigrated from Sweden to America. Would I be able to apply for a citizenship or possibly be eligible for a special visa which would allow me to live/work in Sweden a little bit easier?