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 A090609 #20 Feb 12 2025 16:53:45 %S A090609 11,17,41,101,113,281,317,353,401,617,677,761,941,1433,1613,1697,1877, %T A090609 2273,2297,2381,2693,2801,3461,3677,3701,3881,4937,4973,5441,5573, %U A090609 5861,6581,6737,7673,8237,8681,8933,9137,10181,10337,10733,11261,11597,12101 %N A090609 Primes of the form 6*p - 1 such that p and 6*p - 5 are primes. %F A090609 a(n) = 6*A089144(n) - 1. %t A090609 Select[6Prime[Range[300]]-1,PrimeQ[#]&&PrimeQ[#-4]&] (* _Stefano Spezia_, Feb 12 2025 *) %o A090609 (PARI) lista(nn) = forprime(p=2, nn, if(isprime(6*p-1)&&isprime(6*p-5), print1(6*p-1, ", "))); \\ _Jinyuan Wang_, Aug 04 2021 %Y A090609 Cf. A089144, A090606, A090607, A090608, A090610. %K A090609 nonn,easy %O A090609 1,1 %A A090609 _Ray Chandler_, Dec 06 2003 %E A090609 Name clarified and offset changed to 1 by _Jinyuan Wang_, Aug 03 2021