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 A274239 #13 Sep 08 2022 08:46:17 %S A274239 1,2,5,20,53,161,380,500,530,698,832,833,6353,25433,53921,73538 %N A274239 Numbers n such that 9^n + 8^(n+1) is prime. %C A274239 a(17) > 10^5. %t A274239 Select[Range[0,100000], PrimeQ[9^# + 8^(# + 1)] &] %o A274239 (Magma) [n: n in [0..500] | IsPrime(9^n+8^(n+1))]; // _Vincenzo Librandi_, Jul 12 2016 %o A274239 (PARI) is(n)=ispseudoprime(9^n+8^(n+1)) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A274239 Cf. A093765. %K A274239 nonn,more %O A274239 1,2 %A A274239 _Robert Price_, Jun 15 2016