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 A157006 #29 Nov 26 2023 14:32:54
%S A157006 2,4,6,8,10,20,22,34,70,92,112,118,236,250,378,438,570,654,800,1636,
%T A157006 2848,4948,5670,6772,7494,8006,9056,11038,16268,21416,21738,33370,
%U A157006 78706,112130,126446,164046,219250,236432,368048,524154,530810,640854,699740,746302,754038,754376,931976,989562
%N A157006 Numbers k such that 2^k + 25 is prime.
%C A157006 a(40) > 5*10^5. - _Robert Price_, Oct 15 2015
%C A157006 Since each term is even (n = 2*k), prime numbers of the form 2^k + 25 (see A104072) also have the form 4^k + 25. Those values of k are given in A204388. - _Timothy L. Tiffin_, Aug 06 2016
%H A157006 Henri Lifchitz and Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=2%5En%2B25">Search for 2^n+25</a>, PRP Top Records.
%F A157006 a(n) = 2*A204388(n). - _Timothy L. Tiffin_, Aug 09 2016
%e A157006 For k = 2, 2^2 + 25 = 29.
%e A157006 For k = 4, 2^4 + 25 = 41.
%e A157006 For k = 6, 2^6 + 25 = 89.
%t A157006 Delete[Union[Table[If[PrimeQ[2^n + 25], n, 0], {n, 1, 1000}]], 1]
%t A157006 Select[Range[0, 10000], PrimeQ[2^# + 25] &] (* _Vincenzo Librandi_, Aug 07 2016 *)
%o A157006 (Magma) [n: n in [1..1000] | IsPrime(2^n+25)]; // _Vincenzo Librandi_, Aug 07 2016
%o A157006 (PARI) is(n)=ispseudoprime(2^n+5^2) \\ _Charles R Greathouse IV_, Feb 20 2017
%Y A157006 Cf. A094076, A104072, A123250, A204388.
%Y A157006 Cf. A019434 (primes 2^k+1), A057732 (2^k+3), A059242 (2^k+5), A057195 (2^k+7), A057196 (2^k+9), A102633 (2^k+11), A102634 (2^k+13), A057197 (2^k+15), A057200 (2^k+17), A057221 (2^k+19), A057201 (2^k+21), A057203 (2^k+23), this sequence (2^k+25), A157007 (2^k+27), A156982 (2^k+29), A247952 (2^k+31), A247953 (2^k+33), A220077 (2^k+35).
%K A157006 nonn
%O A157006 1,1
%A A157006 Edwin Dyke (ed.dyke(AT)btinternet.com), Feb 20 2009
%E A157006 Extended by _Vladimir Joseph Stephan Orlovsky_, Feb 27 2011
%E A157006 a(29)-a(39) from _Robert Price_, Oct 15 2015
%E A157006 a(40)-a(48) found by Stefano Morozzi, added by _Elmo R. Oliveira_, Nov 25 2023