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 A217382 #21 May 17 2025 22:45:11 %S A217382 1,2,3,6,10,19,22,109,798,1498,1519,3109,5491,13351,26983,48799,57909, %T A217382 98109 %N A217382 Numbers k such that 8^k + 9 is prime. %C A217382 All terms are equal to 1/3 of the multiples of 3 in A057196. %t A217382 Select[Range[10000], PrimeQ[8^# + 9] &] %o A217382 (PARI) is(n)=ispseudoprime(8^n+9) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A217382 Cf. A057196, A217354, A217355. %Y A217382 Cf. A145440 (associated primes). %K A217382 nonn,more %O A217382 1,2 %A A217382 _Vincenzo Librandi_, Oct 03 2012 %E A217382 a(16)-a(18) from _Michael S. Branicky_, May 17 2025 using b-file at A057196