I think you have written the formula incorrectly. !!!
I think it should be
Be3(PO4)2
In which case it is beryllium phosphate.
As written 'Be3PO42' would indicate that there are '42' oxygens in the molecule. and only one phosphorus.
Brackets are used to indicate the phosphate anion. The '2' is used to inidicate that there are two phosphate anions.