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 A071382 #16 Oct 30 2017 03:52:36 %S A071382 139,173,547,829,2087,2719,3109,10159,56543,80599 %N A071382 Numbers n such that (30^n+1)/31 is a prime. %C A071382 Some of the larger terms may only correspond to probable primes. %C A071382 a(11) > 10^5. - _Robert Price_, Jul 10 2013 %H A071382 H. Dubner and T. Granlund, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/DUBNER/dubner.html">Primes of the Form (b^n+1)/(b+1)</a>, J. Integer Sequences, 3 (2000), #P00.2.7. %H A071382 H. Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a> %t A071382 Select[Range[3000], PrimeQ[(30^# + 1) / 31] &] (* _Vincenzo Librandi_, Oct 29 2017 *) %o A071382 (PARI) isok(n) = (denominator(p=(30^n+1)/31)==1) && isprime(p); \\ _Michel Marcus_, Oct 29 2017 %Y A071382 Cf. A071381. %K A071382 nonn,more %O A071382 1,1 %A A071382 _Rick L. Shepherd_, May 22 2002 %E A071382 a(8) from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008 %E A071382 a(9)-a(10) from _Robert Price_, Jul 10 2013