%I
%S 1,2,2,4,2,6,2,8,4,8,4,24,2,8,8,16,2,32,2,48,12,16,4,96,8,8,8,64,8,96,
%T 2,32,16,8,16,512,4,8,16,192,4,144,8,128,64,16,8,768,4,128,32,128,8,
%U 160,64,256,16,64,4,4608,2,8,96,128,8,384,4,128,16,512,8,8192,8,32,128
%N Number of divisors of 2^n1.
%C a(0) cannot be defined because 0's divisors are an infinite set (every number is a divisor of 0.)
%H Amiram Eldar, <a href="/A046801/b046801.txt">Table of n, a(n) for n = 1..1206</a> (terms 1..500 from T. D. Noe)
%e a(120) = 73728 since 2^1201 has that many divisors.
%t Table[DivisorSigma[0, 2^n  1], {n, 120}] (* _Michael De Vlieger_, Mar 26 2015 *)
%o (PARI) a(n) = numdiv(2^n1); \\ _Michel Marcus_, Dec 15 2013
%o (MAGMA) [DivisorSigma(0, 2^n  1): n in [1..100]]; // _Vincenzo Librandi_, Mar 27 2015
%Y Cf. A000043 (n such that a(n) = 2), A000225 (2^n1).
%K nonn
%O 1,2
%A _Labos Elemer_
%E Typo in example fixed by _Reinhard Zumkeller_, May 15 2010
%E a(0) removed by _J. Lowell_, Mar 26 2015
