A095378 - OEIS

%I #32 Sep 01 2024 15:18:17

%S 1,2,3,4,7,9,10,11,12,19,22,24,47,69,110,131,514,566,644,1340,1761,

%T 3129,17188,48968,49644,65183,67220,75994,90746

%N Integers k for which 1 + A094125(k) = 1 + 3*2^k + 2*3^k is prime.

%e 4 is a term because 1 + 3*2^4 + 2*3^4 = 1 + 162 + 48 = 211 is prime.

%t Select[Range[3200], PrimeQ[1 + 3*2^# + 2*3^#] &] (* _Amiram Eldar_, Aug 18 2024 *)

%o (PARI) lista(kmax) = {for(k = 1, kmax, if(isprime(1 + 3*2^k + 2*3^k), print1(k, ", ")));} \\ _Amiram Eldar_, Aug 18 2024

%Y Cf. A094125, A095379 (associated primes).

%K nonn,more

%O 1,2

%A _Labos Elemer_, Jun 07 2004

%E a(23) from _Michael S. Branicky_, May 07 2024

%E a(24)-a(27) from _Michael S. Branicky_, May 31 2024

%E a(28)-a(29) from _Michael S. Branicky_, Sep 01 2024