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 A301632 #43 May 19 2025 14:21:51
%S A301632 0,1,3,15,45,117,159,3739,3777,9703,10623,21459,86595
%N A301632 Numbers k such that 3^k + k + 1 is a prime.
%C A301632 a(14) > 200000. - _Michael S. Branicky_, May 19 2025
%p A301632 a:=n->`if`(isprime(3^k+k+1),k,NULL): seq(a(k),k=0..6000); # _Muniru A Asiru_, Mar 25 2018
%t A301632 Flatten[{0, Select[Range[5000], PrimeQ[3^# + # + 1] &]}] (* _Vaclav Kotesovec_, Mar 25 2018 *)
%o A301632 (PARI) for(n=0, 1000, if(isprime(3^n+n+1), print1(n", ")))
%Y A301632 A182327 gives the primes.
%Y A301632 Cf. A171058, A173053, A301633.
%K A301632 nonn,more,hard
%O A301632 1,3
%A A301632 _Seiichi Manyama_, Mar 25 2018
%E A301632 a(8)-a(9) from _Muniru A Asiru_, Mar 25 2018
%E A301632 a(10)-a(11) from _Vaclav Kotesovec_, Mar 25 2018
%E A301632 a(12) from _Altug Alkan_, Apr 01 2018
%E A301632 a(13) from _Giovanni Resta_, Apr 06 2018