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 A269834 #19 Sep 13 2024 15:58:54 %S A269834 2,5,17,257,65537 %N A269834 Primes p of the form 2^k + 9*(-1)^k - 8. %C A269834 Union of number 2 and Fermat primes > 3 from A019434; for odd k, the numbers 2^k - 17 are divisible by 3. %C A269834 Also primes p of the form 2^k + 12*(-1)^k - 11 for k >= 0 because for odd k, the numbers 2^k - 23 are divisible by 3. %C A269834 Also primes p of the form 2^k + 1/2*(q + 1)*(-1)^k - 1/2*(q - 1) for k >= 0 where q = prime of the form 3m - 1 > 29 from A003627 because for odd k, the numbers 2^k - q are divisible by 3. %C A269834 Corresponding values of k: 0, 2, 4, 8, 16, ... %o A269834 (Magma) [2^n + 9*(-1)^n - 8: n in [0..1000] | IsPrime(2^n + 9*(-1)^n - 8)]; %Y A269834 Sequence is different from A132198 and A111635. %Y A269834 Cf. A003627, A019434. %K A269834 nonn %O A269834 1,1 %A A269834 _Jaroslav Krizek_, Mar 06 2016