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 A023246 #40 Sep 08 2022 08:44:47 %S A023246 5,7,19,29,79,89,97,127,139,167,317,337,397,419,607,659,709,877,929, %T A023246 1069,1129,1409,1699,1777,2029,2099,2267,2339,2557,2617,2707,2837, %U A023246 2917,2939,3019,3067,3389,3407,3529,3617,3659,3719,4229,4549,4919,5209,5227,5417 %N A023246 Primes that remain prime through 2 iterations of the function f(x) = 3*x + 2. %C A023246 Primes p such that 3*p+2 and 9*p+8 are also primes. - _Vincenzo Librandi_, Aug 04 2010 %C A023246 All terms after the first == 7 or 9 (mod 10). - _Robert Israel_, Sep 12 2016 %H A023246 Robert Israel, <a href="/A023246/b023246.txt">Table of n, a(n) for n = 1..10000</a> %p A023246 select(t -> isprime(t) and isprime(3*t+2) and isprime(9*t+8), [5, seq(seq(10*i+j,j=[7,9]),i=0..10^4)]); # _Robert Israel_, Sep 12 2016 %t A023246 Select[Prime[Range[750]],And@@PrimeQ[Rest[NestList[3#+2&,#,2]]]&] (* _Harvey P. Dale_, May 05 2014 *) %o A023246 (Magma) [n: n in [0..100000] | IsPrime(n) and IsPrime(3*n+2) and IsPrime(9*n+8)] // _Vincenzo Librandi_, Aug 04 2010 %Y A023246 Subsequence of A023208. %K A023246 nonn %O A023246 1,1 %A A023246 _David W. Wilson_