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 A165780 #18 Sep 08 2022 08:45:48
%S A165780 2,3,6,8,10,12,14,16,20,22,26,30,34,36,38,43,44,50,58,64,68,80,116,
%T A165780 142,146,254,296,298,306,396,456,730,876,1004,1006,1051,1094,1776,
%U A165780 1896,1908,2502,2876,3824,3882,4796,4818,5006,5704,6722,8467,9676
%N A165780 Numbers n such that |2^n-16257| is prime.
%C A165780 If p=2^n-16257 is prime, then 2^(n-1)*p is a solution to sigma(x)-2x = 16256 = 2^7*(2^7-1) = 2*A000396(4).
%e A165780 a(7)=14 since 2^14-16257 = 127 is prime.
%e A165780 For exponents a(1)=2 through a(6)=12, we get negative values for 2^a(k)-16257, which are prime in absolute value.
%t A165780 Select[Table[{n, Abs[2^n - 16257]},{n,0,100}], PrimeQ[#[[2]]] &][[All, 1]](* _G. C. Greubel_, Apr 08 2016 *)
%o A165780 (PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(abs(2^n-16257)), print1(n, ", "))); \\ _Altug Alkan_, Apr 08 2016
%o A165780 (Magma) [n: n in [1..1100] |IsPrime(2^n-16257)]; // _Vincenzo Librandi_, Apr 09 2016
%Y A165780 Cf. A096818, A165778, A165779.
%K A165780 nonn
%O A165780 1,1
%A A165780 _M. F. Hasler_, Oct 11 2009
%E A165780 More terms from _Altug Alkan_, Apr 08 2016