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 A154418 #24 Sep 08 2022 08:45:40 %S A154418 19,31,41,71,79,109,131,149,151,181,191,241,251,379,409,421,499,509, %T A154418 541,599,631,659,709,719,769,919,1009,1019,1021,1031,1109,1129,1151, %U A154418 1201,1231,1291,1399,1409,1451,1549,1601,1621,1721,1871,1931,2069,2131,2179 %N A154418 Primes p such that (p^2 + 4)/5 is prime. %C A154418 The primes (p^2 + 4)/5 are 73, 193, 337, 1009, 1249, etc. %C A154418 All terms == 1 or 9 (mod 10). - _Robert Israel_, Sep 16 2016 %H A154418 Vincenzo Librandi, <a href="/A154418/b154418.txt">Table of n, a(n) for n = 1..1000</a> %p A154418 select(p -> isprime(p) and isprime((p^2+4)/5), [seq(seq(10*i+j,j=[1,9]),i=0..1000)]); # _Robert Israel_, Sep 16 2016 %t A154418 Select[Prime[Range[200]], PrimeQ[(#^2 + 4)/5] &] (* _Vincenzo Librandi_, Oct 15 2012 *) %o A154418 (Magma) [p: p in PrimesInInterval(7, 2500) | IsPrime((p^2+4) div 5)]; // _Vincenzo Librandi_, Oct 15 2012 %K A154418 nonn,easy %O A154418 1,1 %A A154418 _Vincenzo Librandi_, Jan 09 2009, Dec 13 2010 %E A154418 Corrected and extended by _Zak Seidov_, Jan 13 2009