A145474 - OEIS

%I #13 Aug 06 2014 05:11:05

%S 13,61,73,109,181,193,241,313,349,373,409,433,541,601,613,661,733,829,

%T 853,1033,1069,1129,1201,1213,1249,1453,1489,1609,1693,1741,1753,1801,

%U 1861,2029,2053,2089,2113,2161,2221,2293,2389,2593,2749,2833,2953,3049

%N Primes p such that (13+p)/2 is prime.

%C All these primes are congruent to 1 mod 12.

%H Edward Jiang, <a href="/A145474/b145474.txt">Table of n, a(n) for n = 1..10000</a>

%p select(t -> isprime(t) and isprime((13+t)/2), [seq(12*k+1, k=1..100)]); # _Robert Israel_, Aug 05 2014

%t aa = {}; k = 13; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, Prime[n]]], {n, 1, 500}];aa

%o (PARI)

%o forprime(p=3,10^4,if(isprime((13+p)/2),print1(p,", "))) \\ _Derek Orr_, Aug 05 2014

%Y Cf. A092109, A145471-A145480.

%K nonn

%O 1,1

%A _Artur Jasinski_, Oct 11 2008