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 A178250 #4 Jul 09 2017 14:56:01
%S A178250 3,2,2,2,2,2,3,2,2,2,2,4,2,3,2,2,3,5,2,2,2,3,3,2,4,2,5,2,5,2,2,7,5,3,
%T A178250 2,9,3,2,2,3,2,31,4,2,2,2,3,2,4,2,108,4,2,2,2,2,3,3,2,2,18,7,3,2,2,2,
%U A178250 4,2,3,2,5,32,108,5,3,2,11,4,15,3,4,19,2,6,2,2,11,107,2,42,4,39,2,2,6,2,3
%N A178250 Least number x such that n^x-n-1 is prime.
%C A178250 Least number x such that x^n-x-1 is prime see A127599.
%t A178250 a = {}; Do[k = 2; While[ ! PrimeQ[n^k - n - 1], k++ ]; AppendTo[a, k], {n, 2, 500}]; a (*Artur Jasinski*)
%t A178250 lnx[n_]:=Module[{x=1},While[!PrimeQ[n^x-n-1],x++];x]; Array[lnx,100,2] (* _Harvey P. Dale_, Jul 09 2017 *)
%Y A178250 Cf. A127599
%K A178250 nonn
%O A178250 2,1
%A A178250 _Artur Jasinski_, May 24 2010