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 A050415 #41 Jul 25 2025 16:03:18
%S A050415 5,13,29,61,509,1021,4093,16381,1048573,4194301,16777213,536870909,
%T A050415 19807040628566084398385987581,83076749736557242056487941267521533,
%U A050415 5316911983139663491615228241121378301,1427247692705959881058285969449495136382746621
%N A050415 Primes of the form 2^k - 3.
%C A050415 If p = 2^k - 3 is in this sequence, then p*2^(k-1) is abundant with abundance 2. - _Claude Morin_, Feb 01 2007
%C A050415 Equivalently, primes which give a prime number when 0's and 1's are interchanged in their binary representation; note that the resulting prime is always 10_2 = 2_10 (see A347476). - _Bernard Schott_, Nov 14 2021
%H A050415 Vincenzo Librandi, <a href="/A050415/b050415.txt">Table of n, a(n) for n = 1..30</a>
%H A050415 Christian Kassel and Christophe Reutenauer, <a href="https://arxiv.org/abs/2507.15780">Pairs of intertwined integer sequences</a>, arXiv:2507.15780 [math.NT], 2025. See p. 12.
%F A050415 a(n) = 2^A050414(n) - 3.
%t A050415 lst={};Do[p=2^n-3;If[PrimeQ[p],AppendTo[lst,p]],{n,0,5*5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jan 27 2009 *)
%t A050415 Select[Table[2^n-3,{n,1,400}],PrimeQ] (* _Vincenzo Librandi_, Dec 08 2011 *)
%o A050415 (Magma) [a: n in [1..200] | IsPrime(a) where a is 2^n-3]; // _Vincenzo Librandi_, Dec 08 2011
%o A050415 (PARI) for(n=3,999,if(ispseudoprime(t=2^n-3),print1(t", "))) \\ _Charles R Greathouse IV_, Jul 02 2013
%Y A050415 Cf. A045768, A050414.
%Y A050415 Subsequence of A347476.
%K A050415 nonn
%O A050415 1,1
%A A050415 _Jud McCranie_, Dec 22 1999