%I
%S 19,29,59,79,89,109,139,149,179,199,229,239,269,349,359,379,389,409,
%T 419,439,449,479,499,509,569,599,619,659,709,719,739,769,809,829,839,
%U 859,919,929,1009,1019,1039,1049,1069,1109,1129,1229,1249,1259,1279,1289
%N Primes of form 10n+9.
%C Also primes of form 5n+4.
%C 5 is quadratic residue of primes of form 10*n1.  _Vincenzo Librandi_, Jun 25 2014
%H Michael B. Porter, <a href="/A030433/b030433.txt">Table of n, a(n) for n = 0..100000</a>
%H A. Granville and G. Martin, <a href="http://www.arXiv.org/abs/math.NT/0408319">Prime number races</a>
%F a(n) = 10*A102700(n) + 9.
%F Union of A132234 and A132236.  _Ray Chandler_, Apr 07 2009
%t Select[Prime@Range[210], Mod[ #, 10] == 9 &] (* _Ray Chandler_, Nov 07 2006 *)
%t Select[Range[9, 1300, 10], PrimeQ] (* _Harvey P. Dale_, Jun 01 2012 *)
%o (PARI) select(n>n%10==9, primes(100)) \\ _Charles R Greathouse IV_, Apr 29 2015
%Y Cf. A045457, A049510, A102700.
%K nonn
%O 1,1
%A _Warut Roonguthai_
%E Extended by _Ray Chandler_, Nov 07 2006
