Are you a member of ravelry? If not, go here: http://www.ravelry.com and join. It is free to join and there are lots of patterns. I just put in free knitted adult sweater in the round, and came up with 1949 items. There are a couple of hats and socks, I am not sure how they got included but Ravelry is a great resource. You can search by type of yarn, needle size, etc. If you click on the picture, there are multiple tabs- DETAILS will give you more info about the pattern, and YARN ideas show suggested yarns and PROJECTS are others who have done the same pattern. You can save your projects, yarn, and favorite patterns. I love Ravelry and am sure that I do not know or use a portion of all the benefits.
Patternfish.com also has patterns. By far the best source, as already mentioned is Ravelry. Under Patterns use Advanced Search, then the filters menu for type of garment, gender, age. If you already have yarn, you can search by yarn weight, yardage and fiber too.
I have developed a list of "favorites" that are all seamless knitting by following the suggestions for Ravelry. There are many free patterns, plus some that have small cost involved, but might serve your needs. Good luck.
Check Ravelry for top down sweaters. Knitting pure and simple has lots of patterns but they are not free. Patons has Upside downers booklet which has top down sweaters. Top down pullovers are knit in the round. Cardigans are back and forth.
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