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 A191469 #34 Sep 08 2022 08:45:57 %S A191469 2,3,6,9,21,25,33,49,54,133,245,255,318,1023,1486,3334,6821,8555, %T A191469 11605,42502,44409,90291,92511,140303 %N A191469 Numbers n such that 7^n - 6 is prime. %C A191469 a(14)=1023 and a(15)=1486 correspond to BPSW strong probable primes (passing PARI's ispseudoprime()). - _Joerg Arndt_, Jun 06 2011 %C A191469 a(25) > 2*10^5. - _Robert Price_, Nov 14 2014 %p A191469 A191469:=n->`if`(isprime(7^n-6),n,NULL): seq(A191469(n), n=1..10^3); # _Wesley Ivan Hurt_, Nov 14 2014 %t A191469 Select[Range[1,5000],PrimeQ[7^#-6]&] (* _Vincenzo Librandi_, Aug 05 2012 *) %o A191469 (Magma) [n: n in [1..1000]| IsPrime(7^n-6)] %o A191469 (PARI) for(n=1, 10^6, if(isprime(7^n-6), print1(n, ", "))) %Y A191469 Cf. A014224, A059266, A059613, A059614, A095714, A177093. %Y A191469 Cf. A236371, A217131, A191469, A090669, A096305, A217130, A217132, A152213. %K A191469 nonn,hard,more %O A191469 1,1 %A A191469 _Vincenzo Librandi_, Jun 06 2011 %E A191469 a(17)-a(23) from _Robert Price_, Jan 24 2014 %E A191469 a(24) from _Robert Price_, Nov 14 2014