Hi, you write: "I am looking for information on descendants of my Great Grandfather Martin Jensen." But I think you are looking only for descendants of Martin's brother Jens, is that right?
I cannot answer your question, but it may be that the Denmark forum can (on Ancestry message boards). Another excellent forum is "Find Your Relatives in Denmark" at http://www.slaegtogdata.dk/
. Another very active board with highly skilled volunteers is on Genforum, Denmark Forum.
Perhaps this family below is your family, in Eriknauer village in Hatting sogn, Hatting herred, Vejle amt, Denmark. (Adding the geography terms "Hatting" and "Vejle" to your thread in this way can help draw Google searching descendants to your particular Jensen request.)
1880 Danish census
Vejle, Hatting, Hatting, Eriknauer By, Hus, 28, FT-1880, C9912
Niels Jensen 42 Gift (married) Husfader Daglejer i Agerbruget, born in Lange Mark, Nørrebjert, Vejle Amt
Karen Jensen 39 Gift, Husmoder, born in Vindelev Vejle Amt
Karoline Jensen 12 Ugift (unmarried) Husmoder (an error-should say "barn"), born in Løsning S. Skanderborg Amt
Maren Jensen 9 Ugift, barn (child), born in Hatting sogn
Jens Jensen 6 Ugift, barn, born in Hatting sogn
Martin Jensen 2 Ugift barn born in Hatting
Kirstine Jensen under 1 aar, Ugift, barn, born in Hatting
All best, a volunteer