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 A145713 #7 May 01 2013 21:11:53 %S A145713 1,10,105,1180,14143,158036,1703161,17520558,157563619,1431557207 %N A145713 Number of primes p in the range 9 < p <= prime(10^n) that begin and end with the same digit. %F A145713 a(n) = A145709(n) + A145710(n) + A145711(n) + A145712(n). [R. J. Mathar, Aug 02 2010] %e A145713 The initial 1 is from the prime 11. %e A145713 a(4)=1180 because to 10^4 or 10000 primes, ending in 104729=A006988(4), there are 1180 primes with equal and distinct first and last digits: 1 and 1, 3 and 3, 7 and 7 and 9 and 9. %Y A145713 Cf. A145709 - A145712 %K A145713 hard,more,nonn,base %O A145713 1,2 %A A145713 _Enoch Haga_, Oct 16 2008 %E A145713 Edited by _N. J. A. Sloane_, Aug 16 2010 %E A145713 a(6) corrected and a(7)-a(10) added by _D. S. McNeil_, Aug 29 2010