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%I #26 Nov 12 2023 09:13:13
%S 2,4,6,8,10,16,18,20,28,30,38,44,78,88,98,126,160,174,204,214,588,610,
%T 798,926,1190,1198,1806,1888,2648,3454,3510,3864,3870,8970,12330,
%U 13330,18876,22338,39718,55006,110784,172470,196434,235710,247280,268408,279320,300874,315268,372950,472258,566496,780284,820356
%N Numbers k such that 2^k + 7 is prime.
%C Naturally all terms are even because (3-1)^(2n+1)+7 is divisible by 3. - _Bruno Berselli_, Oct 03 2012
%H Keith Conrad, <a href="https://kconrad.math.uconn.edu/blurbs/ugradnumthy/squaresandinfmanyprimes.pdf">Square patterns and infinitude of primes</a>, University of Connecticut, 2019.
%H Jon Grantham and Andrew Granville, <a href="https://arxiv.org/abs/2307.07894">Fibonacci primes, primes of the form 2^n-k and beyond</a>, arXiv:2307.07894 [math.NT], 2023.
%F a(n) = 2*A217349(n). - _Elmo R. Oliveira_, Nov 12 2023
%p A057195:=n->if isprime(2^n+7) then n; fi; seq(A057195(n), n=1..1000); # _Wesley Ivan Hurt_, Dec 06 2013
%t Do[ If[ PrimeQ[ 2^n +7 ], Print[n]], { n, 1, 15000 }]
%o (PARI) is(n)=isprime(2^n+7) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y Cf. A104066 (primes of the form 2^k+7).
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Sep 15 2000
%E a(37)-a(51) from _Robert Price_, Dec 06 2013
%E a(51), a(53), a(54) from _Jon Grantham_, Jul 29 2023
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