I purchased 100 shs of Apple on 10/10 and have an unrealized loss as of 11/13. If I sell the 100 shs today and do not purchase Apple until 12/20 can I record the loss in 2018
As long as you did not purchase other shares (even in a DRIP) in the 30 days before and the 30 days after you recognize the loss then you can take the deduction in 2018.
There would also be no problem if you bought shares during the 60 day window and then realized the loss by selling ALL shares in 2018 without a subsequent repurchase within 30 days after realizing that loss.