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 A242177 #17 Sep 08 2022 08:46:08 %S A242177 34,1980,9898 %N A242177 Numbers k such that k*7^k + 1 is prime. %H A242177 G. Loeh, <a href="http://guenter.loeh.name/gc/status.html">Generalized Cullen primes</a> %t A242177 Select[Range[3500], PrimeQ[# 7^# + 1] &] %o A242177 (Magma) [n: n in [0..3500] | IsPrime(n*7^n+1)]; %o A242177 (PARI) is(n)=ispseudoprime(n*7^n+1) \\ _Charles R Greathouse IV_, May 22 2017 %Y A242177 Cf. similar sequences listed in A242176. %K A242177 nonn,more,bref %O A242177 1,1 %A A242177 _Vincenzo Librandi_, May 08 2014 %E A242177 a(3) from Loeh's list (see Links) - _Bruno Berselli_, May 08 2014