A339503 - OEIS

%I #14 Dec 07 2020 20:05:46

%S 5,11,17,41,101,149,179,227,431,461,641,821,1031,1151,1229,1289,1619,

%T 1697,1877,2111,2129,2141,2801,2999,3251,3257,3299,3467,3527,3671,

%U 3917,4001,4049,4931,4967,5501,5519,5639,6299,6359,6689,7307,7349,7487,7547,7877,7949,8009,8291,8429,8597,8819

%N Lesser p of twin primes p,q such that (p*q-2)/3 is prime.

%H Robert Israel, <a href="/A339503/b339503.txt">Table of n, a(n) for n = 1..10000</a>

%e a(3)=17 is a term because 17 and 19 and (17*19-2)/3 = 107 are primes.

%p P:= {seq(ithprime(i),i=3..10000)}:

%p T:= P intersect map(`-`,P,2):

%p select(p -> isprime((p*(p+2)-2)/3), T);

%t Select[Prime@ Range[1100], AllTrue[{#2, (Times @@ {##} - 2)/3}, PrimeQ] & @@ {#, # + 2} &] (* _Michael De Vlieger_, Dec 07 2020 *)

%Y Cf. A001359, A339504.

%K nonn

%O 1,1

%A _J. M. Bergot_ and _Robert Israel_, Dec 07 2020