A letter with a diaeresis (for example fuenf = "five") is still counted as a single letter.
Table of n, a(n) for n=1..16.
a(n) = A007208(A000040(n)). [From R. J. Mathar, Oct 09 2010]
a(1) = 4 because the first prime is 2, and it has in the German language (zwei) 4 letters.
Sequence in context: A006075 A074904 A010304 * A130331 A141241 A140696
Adjacent sequences: A164818 A164819 A164820 * A164822 A164823 A164824
Ivan Panchenko, Aug 27 2009