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 A384697 #18 Jun 17 2025 19:18:04
%S A384697 3,409,6553,1677721,6871947673,472236648286964521369,
%T A384697 7922816251426433759354395033,
%U A384697 2451992865385422173373355243440494693789982595493763481
%N A384697 Primes of the form floor(2^k / 5).
%H A384697 Vincenzo Librandi, <a href="/A384697/b384697.txt">Table of n, a(n) for n = 1..15</a>
%F A384697 a(n) = floor(2^A383966(n)/5).
%t A384697 Select[Table[Quotient[(2^n), 5],{n,1,250}],PrimeQ]
%o A384697 (Magma) [ a: k in [0..500] | IsPrime(a) where a is 2^k div 5 ];
%Y A384697 Cf. A383966 (corresponding k).
%K A384697 nonn
%O A384697 1,1
%A A384697 _Vincenzo Librandi_, Jun 07 2025