A132234 - OEIS

%I #18 Sep 08 2022 08:45:31

%S 19,79,109,139,199,229,349,379,409,439,499,619,709,739,769,829,859,

%T 919,1009,1039,1069,1129,1249,1279,1399,1429,1459,1489,1549,1579,1609,

%U 1669,1699,1759,1789,1879,1999,2029,2089,2179,2239,2269,2389,2539,2659,2689

%N Primes congruent to 19 (mod 30).

%C Also primes congruent to 4 (mod 15). - _N. J. A. Sloane_, Jul 11 2008

%C Primes ending in 9 with (SOD-1)/3 integer where SOD is sum of digits. - _Ki Punches_

%H Vincenzo Librandi, <a href="/A132234/b132234.txt">Table of n, a(n) for n = 1..1000</a>

%H C. K. Caldwell, <a href="http://primes.utm.edu">The Prime Pages</a>.

%H Omar E. Pol, <a href="http://www.polprimos.com">Determinacion geometrica de los numeros primos y perfectos</a>.

%F a(n) = A158806(n)*30 + 19. - Chandler

%F Intersection of A030433 and A002476. - Chandler

%t Select[Prime[Range[1000]],MemberQ[{19},Mod[#,30]]&] (* _Vincenzo Librandi_, Aug 14 2012 *)

%t Select[Range[19,2700,30],PrimeQ] (* _Harvey P. Dale_, Dec 26 2014 *)

%o (Magma) [p: p in PrimesUpTo(3000) | p mod 30 eq 19 ]; // _Vincenzo Librandi_, Aug 14 2012

%o (PARI) is(n)=isprime(n) && n%30==19 \\ _Charles R Greathouse IV_, Jul 01 2016

%Y Cf. A000040, A039949, A132230-A132236.

%K nonn,easy

%O 1,1

%A _Omar E. Pol_, Aug 15 2007

%E Extended by _Ray Chandler_, Apr 07 2009