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 A127197 #18 Jan 21 2024 02:13:09
%S A127197 1,1,1,3,3,1,1,1,1,5,5,3,3,3,3,7,7,1,1,1,1,9,9,9,9,9,9,5,5,11,11,11,
%T A127197 11,11,11,3,3,3,3,13,13,7,7,7,7,15,15,15,15,15,15,1,1,1,1,1,1,17,17,9,
%U A127197 9,9,9,9,9,19,19,19,19,5,5,21,21,21,21,21,21,11,11,11,11,23,23,23,23,23,23
%N A127197 a(n) = numerator( pi(n)/2^n ).
%t A127197 Table[Numerator[PrimePi[k]/2^k], {k, 2, 1000}]
%o A127197 (PARI) a(n) = numerator(primepi(n)/2^n); \\ _Michel Marcus_, Oct 28 2019
%Y A127197 Cf. A000079 (2^n), A000720 (PrimePi), A119523.
%K A127197 nonn,frac
%O A127197 2,4
%A A127197 _Artur Jasinski_, Jan 08 2007
%E A127197 Offset 2 from _Michel Marcus_, Oct 28 2019
%E A127197 New name using formula from _Joerg Arndt_, Jan 20 2024