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 A243279 #10 May 22 2017 12:39:09 %S A243279 2,7,19,67,211,433,2437,2719,19531 %N A243279 Numbers n such that (46^n - 1)/45 is prime. %C A243279 a(10) > 10^5. %C A243279 Numbers corresponding to a(7)-a(9) are probable primes. %C A243279 All terms are prime. %H A243279 Harvey 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 A243279 Henri Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a> %p A243279 A243279:=n->`if`(isprime((46^n - 1)/45), n, NULL); seq(A243279(n), n=1..100000); # _Wesley Ivan Hurt_, Apr 12 2014 %t A243279 Select[Prime[Range[100000]], PrimeQ[(46^# - 1)/45] &] %o A243279 (PARI) is(n)=ispseudoprime((46^n-1)/45) \\ _Charles R Greathouse IV_, May 22 2017 %Y A243279 Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035, A127995, A127996, A127997, A127998, A127999, A098438, A128002, A128003, A128004, A128005, A240765, A242797. %K A243279 hard,more,nonn %O A243279 1,1 %A A243279 _Robert Price_, Jun 02 2014