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 A127200 #7 Oct 28 2019 07:48:08
%S A127200 1,1,5,23,49,51,13,105,211,1693,3391,1697,6791,13585,27173,108699,
%T A127200 217405,217409,217411,54353,434825,6957209,13914427,27828863,55657735,
%U A127200 111315479,222630967,55657743,445261949,1781047807,3562095625
%N A127200 Numerator of n-th partial sum of the Van der Waerden-Ulam binary measure of the primes.
%t A127200 Table[Numerator[Sum[PrimePi[k]/2^k, {k, 2, x}]], {x, 2, 100}]
%o A127200 (PARI) a(n) = numerator(sum(k=2, n, primepi(k)/2^k)); \\ _Michel Marcus_, Oct 28 2019
%Y A127200 Cf. A119523, A127197, A127201.
%K A127200 nonn,frac
%O A127200 2,3
%A A127200 _Artur Jasinski_, Jan 08 2007