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 A046801 #48 Mar 13 2023 11:57:30
%S A046801 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 A046801 2,32,16,8,16,512,4,8,16,192,4,144,8,128,64,16,8,768,4,128,32,128,8,
%U A046801 160,64,256,16,64,4,4608,2,8,96,128,8,384,4,128,16,512,8,8192,8,32,128
%N A046801 Number of divisors of 2^n-1.
%C A046801 a(0) cannot be defined because 0's divisors are an infinite set (every number is a divisor of 0.)
%H A046801 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 A046801 a(120) = 73728 since 2^120-1 has that many divisors.
%p A046801 a:= n-> numtheory[tau](2^n-1):
%p A046801 seq(a(n), n=1..80); # _Alois P. Heinz_, Aug 23 2021
%t A046801 Table[DivisorSigma[0, 2^n - 1], {n, 120}] (* _Michael De Vlieger_, Mar 26 2015 *)
%o A046801 (PARI) a(n) = numdiv(2^n-1); \\ _Michel Marcus_, Dec 15 2013
%o A046801 (Magma) [DivisorSigma(0, 2^n - 1): n in [1..100]]; // _Vincenzo Librandi_, Mar 27 2015
%o A046801 (Python)
%o A046801 from sympy import divisor_count
%o A046801 def A046801(n): return divisor_count((1<<n)-1) # _Chai Wah Wu_, Mar 13 2023
%Y A046801 Cf. A000043 (n such that a(n) = 2), A000225 (2^n-1).
%K A046801 nonn
%O A046801 1,2
%A A046801 _Labos Elemer_
%E A046801 Typo in example fixed by _Reinhard Zumkeller_, May 15 2010
%E A046801 a(0) removed by _J. Lowell_, Mar 26 2015