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 A216890 #16 Sep 08 2022 08:46:04 %S A216890 1,2,3,18,22,26,27,33,39,57,62,94,145,246,390,398,402,571,690,906, %T A216890 1062,1254,1367,1627,1954,2409,3107,14754,15378,24219,46138,98883, %U A216890 161178 %N A216890 Numbers n such that 14*3^n + 1 is prime. %C A216890 The next terms are > 6000. %C A216890 a(34) > 2*10^5. - _Robert Price_, Mar 16 2014 %C A216890 All terms are verified primes (i.e., not probable primes). - _Robert Price_, Mar 16 2014 %t A216890 Select[Range[4000], PrimeQ[14 3^# + 1] &] %o A216890 (Magma) [n: n in [0..4000] | IsPrime(14*3^n+1)]; %o A216890 (PARI) is(n)=ispseudoprime(14*3^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A216890 Cf. A003306, A005537-A005539, A056805. %K A216890 nonn %O A216890 1,2 %A A216890 _Vincenzo Librandi_, Sep 26 2012 %E A216890 a(28)-a(33) from _Robert Price_, Mar 16 2014