Letter sequence

[Bilko]

What is the next letter in this incomplete NUMERICAL sequence.
N E E I U F X ?

Any ideas please as I'm somewhat mystified about the number reference

[sarumite]

I think it is V as the third letter of the number seventeen. The sequence is based on the third letters of numbers starting from teN, elEven, twElve, etc.

[mac44]

V. Write ten to seventeen downwards, then look at the third row of letters.

[Argee2]

VEry impressive, sarumite and mac44. I would never have thought of that.

[sarumite]

Argee2 ... I seem to remember reference to this previously somewhere, so can't take full credit for coming up with the answer!

[Argee2]

It is surprising what is hidden away in the depths of the grey matter! It is being able to recall it when you need it that is the useful bit, but I think that doing crosswords and puzzles keeps the brain active. It is my birthday in twenty minutes so I am off to bed or the birthday fairy won't come! Good night.

[mac44]

Happy Birthday Argee2