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 A243397 #50 Oct 09 2024 07:36:49 %S A243397 0,1,3,21,145,273,1425,9613,15711,18445 %N A243397 Numbers n such that 19^n+4 is prime. %C A243397 No further terms up to 20000. - _Felix Fröhlich_, Oct 29 2014 %C A243397 No further terms up to 24000. - _Felix Fröhlich_, Jan 22 2015 %C A243397 No further terms up to 50000. - _Michael S. Branicky_, Oct 09 2024 %t A243397 Select[Range[0, 10000], PrimeQ[19^# + 4] &] (* _Vincenzo Librandi_, Oct 16 2014 *) %o A243397 (PARI) for(n=0, 10^5, if(ispseudoprime(19^n+4), print1(n, ", "))) %o A243397 (Magma) [n: n in [0..1000] | IsPrime(19^n+4)]; // _Vincenzo Librandi_, Oct 16 2014 %Y A243397 Corresponding sequences for k^n+4: A058958 (k=3), A124621 (k=5), A096305 (k=7), A217384 (k=9), A137236 (k=13). %K A243397 nonn,more %O A243397 1,3 %A A243397 _Felix Fröhlich_, Jun 04 2014 %E A243397 a(1)-a(2) prepended by _N. J. A. Sloane_, Jun 18 2014 %E A243397 a(9)-a(10) from _Felix Fröhlich_, Oct 16 2014