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 A100408 #12 Dec 08 2024 18:40:48
%S A100408 2,7,19,21,25,49,51,1071
%N A100408 Numbers n such that n^n-2 is prime.
%C A100408 Except for the first term all terms are odd.
%C A100408 Numbers n such that n^n+7 is prime gives the (as yet) too-short sequence 2,4,6,32,...
%C A100408 If it exists, a(9) > 25000. - _Robert Price_, Apr 25 2019
%e A100408 51 is in the sequence because 51^51-2 is prime. 1071^1071-2 is a probable prime.
%t A100408 Do[If[PrimeQ[n^n-2], Print[n]], {n, 1111}]
%t A100408 Select[Range[1111],PrimeQ[#^#-2]&] (* _Harvey P. Dale_, Dec 08 2024 *)
%o A100408 (PARI) is(n)=ispseudoprime(n^n-2) \\ _Charles R Greathouse IV_, Feb 20 2017
%Y A100408 Cf. A100407.
%K A100408 more,nonn
%O A100408 1,1
%A A100408 _Farideh Firoozbakht_, Nov 19 2004