OFFSET
0,2
LINKS
Harry J. Smith, Table of n, a(n) for n=0..50
FORMULA
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
a(n) ~ 2^(n^2) / n!. - Vaclav Kotesovec, Jul 02 2016
MAPLE
MATHEMATICA
Table[Sum[Binomial[2^n, k], {k, 0, n}], {n, 0, 15}] (* Vaclav Kotesovec, Jul 02 2016 *)
PROG
(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
(Sage) [sum(binomial(2^n, k) for k in (0..n)) for n in (0..20)] # G. C. Greubel, Mar 15 2021
(Magma) [(&+[Binomial(2^n, k): k in [0..n]]): n in [0..20]]; // G. C. Greubel, Mar 15 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 23 2001
STATUS
approved