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 A091937 #6 Mar 30 2012 18:50:43
%S A091937 2,3,3,5,5,7,7,8,9,10,11,13,13,13,15,17,17,19,19,20,21,21,23,24,25,25,
%T A091937 27,28,29,31,31,32,33,34,35,35,37,37,39,40,41,41,43,44,45,46,47,48,49,
%U A091937 50,51,52,53,53,55,56,56,58,59,61,61,61,63,64,65,66,67,68,69,69,71,72
%N A091937 Greatest number of 1's in binary representations of primes between 2^n and 2^(n+1).
%C A091937 a(n) = A000120(A091938(n)).
%t A091937 Run the second Mathematica line of A091938, then Count[ IntegerDigits[ #, 2], 1] & /@ Table[ f[n], {n, 75}]
%Y A091937 Cf. A091935.
%K A091937 nonn
%O A091937 1,1
%A A091937 _Reinhard Zumkeller_, Feb 14 2004
%E A091937 More terms from _Robert G. Wilson v_, Feb 20 2004