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 A319217 #24 Sep 08 2022 08:46:23 %S A319217 4,9,13,38,42,67,133,134,142,155,167,226,654,5787,6703,12704,25969, %T A319217 70198,78060,235304 %N A319217 Integers k such that (13*2^k)^8 + 1 is prime. %C A319217 These numbers are a subset of Generalized Fermat Primes power 8. %C A319217 All numbers from 1 to 235763 has been checked by LLR, no other primes found. %C A319217 k is not congruent to 6 mod 25 because otherwise (13*2^k)^8+1 would be divisible by 401. - _Bruno Berselli_, Sep 21 2018 %H A319217 Chris K. Caldwell, <a href="https://primes.utm.edu/primes/page.php?id=125613">The Prime Database: 815730721*2^1882432+1</a> %e A319217 4 is a term because (13*2^4)^8+1 = 3503536769037500417 is a prime number. %t A319217 Select[Range[700], PrimeQ[(13 2^#)^8 + 1] &] (* _Vincenzo Librandi_, Sep 21 2018 *) %o A319217 (Magma) [n: n in [1..700] | IsPrime((13*2^n)^8+1)]; // _Vincenzo Librandi_, Sep 21 2018 %o A319217 (PARI) isok(k) = ispseudoprime((13*2^k)^8+1); \\ _Altug Alkan_, Sep 21 2018 %K A319217 nonn,hard,more %O A319217 1,1 %A A319217 _Lei Zhou_, Sep 13 2018