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 A191717 #11 Apr 11 2025 11:28:23 %S A191717 3,5,18,23,78,131,177 %N A191717 Numbers k such that k*(k-1)^k - (k-1)*k^(k-1) + 1 is prime. %D A191717 a(8) > 20000. - _Michael S. Branicky_, Apr 11 2025 %e A191717 a(1)=3 because 3*2^3-2*3^2+1=7 is prime, a(2)=5 because 5*4^5-4*5^4+1=2621 is prime. %o A191717 (PARI) is(n)=ispseudoprime(n*(n-1)^n-(n-1)*n^(n-1)+1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A191717 Cf. A191699, A191715. %K A191717 nonn,hard,more %O A191717 1,1 %A A191717 _Juri-Stepan Gerasimov_, Jun 12 2011