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 A366811 #18 Nov 30 2024 06:26:25
%S A366811 2,2,2,2,2,2,4,8,4,4,8,2,8,8,4,8,16,16,4,4,16,4,8,4,16,8,4,16,16,8,8,
%T A366811 32,8,64,4,8,4,32,16,16,4,64,8,16,8,32,64,128,4,64,8,32,8,16,4,64,32,
%U A366811 16,32,8,32,32,32,8,8,32,32,64,8,16,16,128,32,8,16
%N A366811 The number of divisors of prime(n)#+1 where p# is the product of all the primes from 2 to p inclusive.
%H A366811 Amiram Eldar, <a href="/A366811/b366811.txt">Table of n, a(n) for n = 0..98</a>
%F A366811 a(n) = sigma0(prime(n)#+1) = A000005(A006862(n)).
%e A366811 a(6) = 4 because the divisors of 13#+1 = 30031 are {1, 59, 509, 30031}.
%p A366811 seq(numtheory[tau](mul(ithprime(k), k=1..n)+1), n=0..30);
%t A366811 Map[DivisorSigma[0, #] &, 1 + FoldList[Times, 1, Prime@ Range@ 19] ] (* _Michael De Vlieger_, Oct 25 2023 *)
%Y A366811 Cf. A006862, A000005, A054988, A366808, A366812, A064145.
%K A366811 nonn
%O A366811 0,1
%A A366811 _Sean A. Irvine_, Oct 23 2023