This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A214506 #23 Feb 23 2014 02:52:57
%S A214506 2,1,1,9,7,3,3,9,7,7,9,3,9,7,1,7,1,3,3,1,9,7,9,7,7,3,7,3,1,9,7,3,9,1,
%T A214506 3,9,7,3,3,3,1,9,3,7,1,9,1,3,3,9,1,1,7,1,1,1,3,9,9,9,7,3,7,1,7,9,9,9,
%U A214506 9,9,3,3,9,9,7,9,3,1,3,9,9,3,1,7,1,3
%N A214506 Last digit of the smallest prime number in base 10 with n digits.
%C A214506 The last digit of the first prime number in base 10 with n digits for n = 1, 2, 3 is 211, because 2 is the least with 1 digit, 11 the least with 2 digits, 101 the least with 3 digits. The concatenation, 211, is prime. This does not happen again through 24 digits. - _Jonathan Vos Post_, Jul 04 2012
%F A214506 a(1) = 2, and a(n) = A033873(n) mod 10 for n>1.
%F A214506 a(n) = A003617(n) mod 10. - _Michel Marcus_, Aug 06 2013
%t A214506 Table[Mod[NextPrime[10^n],10],{n,0,30}] (* _Harvey P. Dale_, Jan 25 2013 *)
%K A214506 nonn,base
%O A214506 1,1
%A A214506 _Tjandra Satria Gunawan_, Jul 19 2012
%E A214506 More terms from _Harvey P. Dale_, Jan 25 2013