Qn is a 2 letter English word.
You can make 4 anagrams from letters in QN (nq).
From the Latin word quoque nocte
He is ordainit to labour it, and promist to do so efter Whitsonday, QN it was for faching.
If we divide Pn by QN, we shall find a series agreeing with the known series for tan x, as far as n terms.