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 A181979 #16 Mar 14 2016 03:30:23 %S A181979 5,151,3719,49211,77237 %N A181979 Numbers n such that (29^n - 1)/28 is prime. %H A181979 H. Dubner, <a href="http://dx.doi.org/10.1090/S0025-5718-1993-1185243-9">Generalized repunit primes</a>, Math. Comp., 61 (1993), 927-930. %H A181979 H. Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a> %H A181979 <a href="/index/Pri#primepop">Index to primes in various ranges</a>, form ((k+1)^n-1)/k %t A181979 Select[Prime[Range[100000]], PrimeQ[(29^#-1)/28]&] %o A181979 (PARI) isok(n) = isprime((29^n-1)/28); \\ _Michel Marcus_, Mar 13 2016 %K A181979 hard,more,nonn %O A181979 1,1 %A A181979 _Robert Price_, Apr 04 2012