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 A254665 #7 Sep 08 2022 08:46:11 %S A254665 3,71,79,89,101,199,271,281,293,349,359,433,463,479,569,577,641,659, %T A254665 701,743,769,787,809,839,863,911,953,1013,1033,1049,1109,1181,1249, %U A254665 1277,1321,1361,1399,1429,1451,1459,1481,1511,1549,1571,1627,1693,1733,1759,1889 %N A254665 Primes prime(n) such that prime(n) + 7*n is also prime. %e A254665 prime(2)=3 is in the sequence because 3+7*2 = 17 is prime. %e A254665 prime(20)=71 is in the sequence because 71+7*20 = 211 is prime. %t A254665 Prime[Select[Range[300], PrimeQ[Prime[#] + 7# ]&]] %o A254665 (Magma) [NthPrime(n): n in [1..300] | IsPrime(NthPrime(n)+7*n)]; %Y A254665 Cf. A061067, A231232, A231383, A254462. %K A254665 nonn %O A254665 1,1 %A A254665 _Vincenzo Librandi_, Feb 04 2015