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 A168447 #10 Sep 08 2022 08:45:49 %S A168447 13,17,19,23,31,43,47,67,71,79,83,103,107,139,179,191,223,227,251,263, %T A168447 283,359,367,431,439,443,479,499,503,587,607,619,643,647,659,683,787, %U A168447 823,827,839,907,911,947,983,1039,1087,1091,1151,1163,1187,1367,1399 %N A168447 Primes p such that floor(p/6) is also prime. %H A168447 Vincenzo Librandi, <a href="/A168447/b168447.txt">Table of n, a(n) for n = 1..1000</a> %F A168447 a(n) >> n log^2 n. - _Charles R Greathouse IV_, Feb 23 2017 %t A168447 Select[Prime[Range[6! ]],PrimeQ[Floor[ #/6]]&] %o A168447 (Magma) [p: p in PrimesUpTo(1400) | IsPrime(Floor(p/6))]; // _Vincenzo Librandi_, Apr 16 2013 %o A168447 (PARI) is(n)=isprime(n) && isprime(n\6) \\ _Charles R Greathouse IV_, Feb 23 2017 %Y A168447 Cf. A075519, A168446. %K A168447 nonn,easy %O A168447 1,1 %A A168447 _Vladimir Joseph Stephan Orlovsky_, Nov 25 2009 %E A168447 Definition corrected by _R. J. Mathar_, Dec 06 2009