n = nine
The letters are the first letter of each number when you count. O = One, T = Two, T = Three, F = Four, etc.
n and t like nine and ten
N T
Nine & Ten
Nt
J
E
I is the next letter.
P
E dEsEr....E
e
E
m
l
G
u n p
f, s, e, t First initials of even numbers
E
In the English alphabet Z is the last letter, on a qwerty keyboard the next letter is X and if you thinking of a Zebra then it's e. Actually, after Zedd comes Yuzz. Yes -- it does exist.