A370157 - OEIS

%I #8 Feb 17 2024 12:39:27

%S 2,31,47,61,67,73,101,107,109,137,151,157,181,191,193,211,223,229,241,

%T 263,271,277,281,283,307,331,347,359,373,379,389,401,421,431,443,461,

%U 463,467,487,509,541,547,557,563,571,587,601,613,617,619,631,641,647

%N Primes p such that both 3p+2 and (p-2)/3 are composite or 0.

%t Select[Prime[Range[200]], ! PrimeQ[3 # + 2] && ! PrimeQ[(# - 2)/3] &]

%o (PARI) isok(p) = if (isprime(p), !isprime(3*p+2) && !(((p%3) == 2) && isprime((p-2)/3))); \\ _Michel Marcus_, Feb 17 2024

%Y Cf. A000040, A115058 (supersequence), A023208, A370156.

%K nonn

%O 1,1

%A _Clark Kimberling_, Feb 10 2024