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 A273942 #18 Jul 27 2025 08:47:55
%S A273942 11,6569,16677181699666603
%N A273942 Primes of the form 3^k + k.
%C A273942 Terms given correspond to k in A057900.
%C A273942 a(4) has 731 digits.
%H A273942 Amiram Eldar, <a href="/A273942/b273942.txt">Table of n, a(n) for n = 1..4</a>
%F A273942 a(n) = A104743(A057900(n)). - _Amiram Eldar_, Jul 27 2025
%t A273942 Select[Table[3^n + n, {n, 1, 1000}], PrimeQ]
%o A273942 (Magma) [a: n in [0..100] | IsPrime(a) where a is 3^n+n];
%Y A273942 Cf. A057900, A104743, A129962, A129963.
%K A273942 nonn,hard
%O A273942 1,1
%A A273942 _Vincenzo Librandi_, Jun 06 2016