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 A066384 #22 Mar 17 2021 15:31:58
%S A066384 1,3,11,93,2517,242825,83278001,100224990433,423203101008289,
%T A066384 6320756952791172417,337588530920463407788161,
%U A066384 65183827170777713040896325889,45946801057461743411385200045344257,119218150804947710897541255907308439677953,1146646393160535279886911833912593527834996340737
%N A066384 a(n) = Sum_{k=0..n} binomial(2^n,k).
%H A066384 Harry J. Smith, <a href="/A066384/b066384.txt">Table of n, a(n) for n=0..50</a>
%F A066384 G.f.: Sum_{n>=0} log(1+2^n*x)^n/((1-2^n*x)*n!). - _Paul D. Hanna_ and _Vladeta Jovovic_, Jan 15 2008
%F A066384 a(n) ~ 2^(n^2) / n!. - _Vaclav Kotesovec_, Jul 02 2016
%p A066384 A066384:= n-> add(binomial(2^n, k), k=0..n); seq(A066384(n), n=0..20); # _G. C. Greubel_, Mar 15 2021
%t A066384 Table[Sum[Binomial[2^n,k], {k, 0, n}], {n, 0, 15}] (* _Vaclav Kotesovec_, Jul 02 2016 *)
%o A066384 (PARI) a(n) = sum(k=0, n, binomial(2^n, k)); \\ _Harry J. Smith_, Feb 12 2010; modified by _G. C. Greubel_, Mar 15 2021
%o A066384 (Sage) [sum(binomial(2^n, k) for k in (0..n)) for n in (0..20)] # _G. C. Greubel_, Mar 15 2021
%o A066384 (Magma) [(&+[Binomial(2^n, k): k in [0..n]]): n in [0..20]]; // _G. C. Greubel_, Mar 15 2021
%K A066384 nonn
%O A066384 0,2
%A A066384 _N. J. A. Sloane_, Dec 23 2001