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 A180745 #43 Oct 14 2024 23:57:35 %S A180745 1,4,8,140,32060 %N A180745 Numbers k such that 7^k - 5^k + 1 is prime. %C A180745 No further terms k <= 5000. - _Harvey P. Dale_, Jan 25 2011 %C A180745 No further terms k <= 10000. - _Tyler NeSmith_, May 06 2021 %C A180745 No further terms k <= 20000. - _Jon E. Schoenfield_, May 07 2021 %C A180745 No further terms k <= 100000. - _Lucas A. Brown_, Oct 14 2024 %t A180745 Select[Range[5000],PrimeQ[7^#-5^#+1]&] (* _Harvey P. Dale_, Jan 25 2011 *) %o A180745 (Magma) [n: n in [0..1000]|IsPrime(7^n-5^n+1)]; %o A180745 (PARI) is(n)=ispseudoprime(7^n-5^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A180745 Cf. A155640. %K A180745 nonn,hard,more %O A180745 1,2 %A A180745 _Vincenzo Librandi_, Jan 22 2011 %E A180745 a(5) from _Michael S. Branicky_, Mar 31 2023