This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A024903 #21 Sep 08 2022 08:44:48 %S A024903 1,3,5,9,11,15,23,29,33,35,39,41,45,51,53,59,69,75,81,83,89,93,95,111, %T A024903 113,119,123,135,141,143,149,159,161,165,171,179,183,185,189,195,209, %U A024903 213,221,225,231,233,239,243,251,261,269,273,279,299,305,321,335,341 %N A024903 Numbers k such that 7*k - 4 is prime. %H A024903 Vincenzo Librandi, <a href="/A024903/b024903.txt">Table of n, a(n) for n = 1..1000</a> %F A024903 a(n) = A033868(n-1)-1 = A089033(n-1)+1 = A090614(n-1)*2+1. %t A024903 Select[Range[350], PrimeQ[7 # - 4] &] (* _Vincenzo Librandi_, Sep 26 2012 *) %o A024903 (Magma) [n: n in [1..400] | IsPrime(7*n-4)]; // _Vincenzo Librandi_, Nov 20 2010 %o A024903 (PARI) is(n)=isprime(7*n-4) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A024903 Cf. A045437 (associated primes), A090613 (gives prime index). %Y A024903 Cf. A033868, A089033, A090614. %K A024903 nonn,easy %O A024903 1,2 %A A024903 _Clark Kimberling_