A145712 - OEIS

%I #6 May 01 2013 21:11:53

%S 0,0,2,245,2053,17518,153645,1362970,12244431,111153241

%N Number of primes p in the range 9 < p <= prime(10^n) that have most significant and least significant decimal digit both equal to 9.

%e a(3)=2 because out of the first 1000 primes, only two have first and last digits 9, 919 and 929.

%Y Cf. A145709 A145710 A145711 A145713

%K hard,nonn,base

%O 1,3

%A _Enoch Haga_, Oct 16 2008

%E Better definition from R. J. Mathar, Aug 04 2010

%E Edited and corrected by _N. J. A. Sloane_, Aug 16 2010

%E a(7)-a(10) from _D. S. McNeil_, Aug 29 2010