We introduce DeReKoGram, a novel frequency dataset containing lemma and part-of-speech (POS) information for 1-, 2-, and 3-grams from the German Reference Corpus. The dataset contains information based on a corpus of 43.2 billion tokens and is divided into 16 parts based on 16 corpus folds. We describe how the dataset was created and structured. By evaluating the distribution over the 16 folds, we show that it is possible to work with a subset of the folds in many use cases (e.g. to save computational resources). In a case study, we investigate the growth of the vocabulary (as well as the number of hapax legomena) as more and more folds are included into the analysis. We cross-combine this with several cleaning stages of the dataset. We also give some guidance in the form of Python, R and Stata markdown scripts on how to work with the resource.