Table of n, a(n) for n=1..15.
Arndt Bruenner, Table of Latin numerals
a(1) = 3, because the first prime number is 2 and it contains 3 letters in Latin.
Sequence in context: A284326 A117553 A290270 * A120224 A210471 A183107
Adjacent sequences: A168272 A168273 A168274 * A168276 A168277 A168278
Ivan Panchenko, Nov 22 2009