What would be the formula for diphosphorus pentoxide?

Here's my thought process:

• From name: phosphorus ##->## ##"P"##
• "di" ##->## ##2##
• From name: oxide ##->## ##"O"##
• Anion stem: "ox"
• "pent" (instead of "penta", since "ox" starts with a vowel) ##->## ##5##

##->## ##"P"_2"O"_5## (empirical formula)