This database contains a total of three hundred thousands (300.000) oligonucleotide sequences in a size range between 16 and 30 bases. For each oligonucleotide length, 20.000 sequences are available, which are distributed homogeneously in 10 classes of CG-content percentage. Thus, for each particular length and CG-content class, a total of 2.000 oligonucleotide sequences are available. For each oligonucleotide sequence, several features and properties were extracted and/or calculated, and stored in this database. The raw data used to build this database can be downloaded as a raw text file (38 MB) or as a gzipped file (7 MB).