Question: Which country participated in the Eurovision Song contest in 1957 but absent in 1970 and submitted the song co-written by Sebastian F. Ovens?
Sentence (from "Soldiers of Love (Lighthouse X song)"): The song represented Denmark in the Eurovision Song Contest 2016, and was written by the band along with Sebastian F. Ovens, Daniel Lund Jørgensen, and Katrine Klith Andersen.
Relevant evidence: Yes