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 A023255 #21 Sep 08 2022 08:44:47 %S A023255 7,13,19,31,43,73,211,223,241,307,397,409,631,661,727,757,769,829,883, %T A023255 1123,1741,1783,1867,2131,2143,2269,2287,2467,2521,2551,2857,2917, %U A023255 3253,3319,3793,3967,4297,4423,4597,4957,5449,5563,5701,6229,6427,6469,6679 %N A023255 Primes that remain prime through 2 iterations of the function f(x) = 5x + 8. %C A023255 Primes p such that 5*p+8 and 25*p+48 are also primes. - _Vincenzo Librandi_, Aug 04 2010 %H A023255 John Cerkan, <a href="/A023255/b023255.txt">Table of n, a(n) for n = 1..10000</a> %F A023255 a(n) == 1 (mod 6). - _John Cerkan_, Sep 14 2016 %t A023255 fQ[n_]:=And@@PrimeQ[NestList[5#+8&,n,2]]; Select[Range[7000],fQ] (* _Harvey P. Dale_, Mar 25 2013 *) %o A023255 (Magma) [n: n in [0..100000] | IsPrime(n) and IsPrime(5*n+8) and IsPrime(25*n+48)] // _Vincenzo Librandi_, Aug 04 2010 %Y A023255 Subsequence of A023220, A111225. %K A023255 nonn %O A023255 1,1 %A A023255 _David W. Wilson_