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 A072056 #14 Apr 26 2024 05:58:21
%S A072056 2,2,2,4,2,4,4,4,2,2,6,6,2,4,4,2,4,4,8,4,6,4,2,2,8,4,6,4,4,2,8,2,6,6,
%T A072056 4,4,12,4,4,2,2,6,2,6,4,8,6,4,8,8,2,2,8,2,4,4,6,4,8,2,10,2,8,4,8,4,8,
%U A072056 12,4,4,4,2,12,6,8,4,4,8,4,12,2,4,2,6,4,2,4,8,4,6,8,4,12
%N A072056 Number of divisors of 2*prime(n)+1.
%H A072056 Amiram Eldar, <a href="/A072056/b072056.txt">Table of n, a(n) for n = 1..10000</a>
%F A072056 a(n) = A000005(A072055(n)).
%e A072056 Divisors of A072055(8) = 2*A000040(8)+1 = 2*19+1=39: {1,3,13,39} with size 4, therefore a(8) = 4.
%t A072056 Table[DivisorSigma[0,2Prime[n]+1],{n,100}] (* _Harvey P. Dale_, Apr 12 2021 *)
%o A072056 (PARI) a(n) = numdiv(2*prime(n)+1); \\ _Amiram Eldar_, Apr 26 2024
%o A072056 (PARI) lista(pmax) = forprime(p = 2, pmax, print1(numdiv(2*p+1), ", ")); \\ _Amiram Eldar_, Apr 26 2024
%Y A072056 Cf. A000005, A000040, A072055, A072057.
%K A072056 nonn
%O A072056 1,1
%A A072056 _Reinhard Zumkeller_, Jun 11 2002