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 A215443 #20 Jun 01 2025 13:12:46 %S A215443 1,3,9,13,27,225,505,1605,7417,9193,9235 %N A215443 Numbers k such that 5^k + k^5 - 1 is prime. %C A215443 a(12) > 2*10^5. - _Robert Price_, May 24 2014 %t A215443 Select[Range[0, 3000], PrimeQ[5^# + #^5 - 1] &] %o A215443 (Magma) [k: k in [0..300] | IsPrime(5^k + k^5 - 1)]; %o A215443 (PARI) is(n)=ispseudoprime(5^n+n^5-1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A215443 Cf. A215437. %K A215443 nonn,more %O A215443 1,2 %A A215443 _Vincenzo Librandi_, Sep 03 2012 %E A215443 a(9)-a(11) from _Robert Price_, May 24 2014