Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #21 Feb 12 2020 01:47:57
%S 23,53,131,173,233,263,563,593,653,1013,1223,1283,1601,1613,2333,2543,
%T 2963,3323,3533,3761,3911,3923,4013,4211,4253,4643,4793,5003,5273,
%U 5471,5843,5861,6263,6353,6563,6653,6863,7121,7451,7481,7541,7583
%N p, p+6 and p+8 are all primes (A046138) but p+2 is not.
%H R. J. Mathar, <a href="/A049438/b049438.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Prime@ Range[10^3], MatchQ[Boole@ PrimeQ@ {# + 2, # + 6, # + 8}, {0, 1, 1}] &] (* _Michael De Vlieger_, Feb 05 2017 *)
%o (PARI) isok(p) = isprime(p) && !isprime(p+2) && isprime(p+6) && isprime(p+8); \\ _Michel Marcus_, Dec 13 2013
%Y Subsequence of A031924. - _R. J. Mathar_, Jun 15 2013
%Y Cf. A007530, A023202, A031926, A046134, A046138, A049436, A049437.
%K nonn,easy
%O 1,1
%A _Labos Elemer_