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 A057909 #18 Mar 02 2024 04:01:21
%S A057909 1,3,9,15,37,85,133,225,1233,12793,108889
%N A057909 Numbers k such that 4^k + k is prime.
%C A057909 a(11) > 20000. - _Jinyuan Wang_, Feb 01 2020
%t A057909 Do[ If[ PrimeQ[ 4^n + n ], Print[ n ] ], {n, 0, 3000} ]
%o A057909 (PARI) is(n)=ispseudoprime(4^n+n) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y A057909 Cf. A052007, A057900.
%Y A057909 Cf. A158879 (4^n + n).
%K A057909 nonn,more
%O A057909 1,2
%A A057909 _Robert G. Wilson v_, Nov 16 2000
%E A057909 a(10) from _Jinyuan Wang_, Feb 01 2020
%E A057909 a(11) from _Hugo Pfoertner_, Mar 02 2024