Hrastje may refer to:In Croatia:*Hrastje, Croatia, a village in the Municipality of Sveti Ivan ZelinaIn Slovenia:*Hrastje, Kranj, a settlement in the Municipality of Kranj*Hrastje, Maribor, a settlement in the Municipality of Maribor*Hrastje, Šentjernej, a settlement in the Municipality of Šentjernej*Hrastje, Šentjur, a settlement in the Municipality of Šentjur*Hrastje–Mota, a settlement in the Municipality of Radenci*Hrastje ob Bistrici, a former settlement in the Municipality of Bistrica ob Sotli*Hrastje pri Cerkljah, a settlement in the Municipality of Brežice*Hrastje pri Grosupljem, a settlement in the Municipality of Grosuplje*Hrastje pri Mirni Peči, a settlement in the Municipality of Mirna Peč
Prve praštevilske vrzeli so :: 1, 2, 2, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 6, 6, 2, 6, 4, 2, 6, 4, 6, 8, 4, 2, 4, 2, 4, 14== Preprosti izsledki ==Za poljubno praštevilo "P", večje od 2, je zaporedje:: "P"# + 2, "P"# + 3, ..., "P"# + ("P"n+1-1)zaporedje "P"n+1-2 zaporednih sestavljenih celih števil, ki vsebuje praštevilsko vrzel dolžine vsaj "P"n+1-1.