A153183 - OEIS

%I #25 Oct 05 2024 04:32:17

%S 3,5,7,11,13,15,21,23,25,27,33,35,37,43,47,51,53,55,61,65,67,71,75,77,

%T 81,91,93,95,103,105,111,113,117,123,125,127,133,137,141,145,147,153,

%U 155,163,167,175,181,183,191,193,201,203,205,207,211,215,221,225,231

%N Numbers k such that 3k-2 is prime.

%H Vincenzo Librandi, <a href="/A153183/b153183.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A024892(n)+1. - _Klaus Brockhaus_, Dec 21 2008

%t Select[Range[1, 250], PrimeQ[(3*#)-2]&] (* _Vincenzo Librandi_, Sep 24 2012 *)

%o (Magma) [ n: n in [1..235] | IsPrime(3*n-2) ]; // _Klaus Brockhaus_, Dec 21 2008

%o (PARI) is(n)=isprime(3*n-2) \\ _Charles R Greathouse IV_, Feb 17 2017

%Y Cf. A153184 (complement)

%Y Cf. A088878 (3p-2 is prime), A024892 (3*k+1 is prime).

%K nonn,easy

%O 1,1

%A _Vincenzo Librandi_, Dec 20 2008

%E More terms from _Klaus Brockhaus_, Dec 21 2008