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 A216619 #16 Jul 12 2018 11:34:20 %S A216619 2,8,1592,2380 %N A216619 Numbers k such that 10^k + k^10 - 1 is prime. %C A216619 Next term > 10^4. %C A216619 a(5) > 10^5. - _Robert Price_, Oct 08 2015 %t A216619 Select[Range[0, 5000], PrimeQ[10^# + #^10 - 1] &] %o A216619 (PARI) is(n)=ispseudoprime(10^n+n^10-1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A216619 Cf. A100357, A215434-A215446, A216375. %K A216619 nonn,hard,more %O A216619 1,1 %A A216619 _Vincenzo Librandi_, Sep 11 2012