login
Number of divisors of 11^n+1.
11

%I #7 Jan 04 2024 17:05:18

%S 2,6,4,18,4,12,16,12,8,48,8,96,16,48,32,144,8,48,32,96,16,72,16,96,

%T 128,48,8,240,64,48,64,96,16,4608,64,1152,128,24,16,1152,32,48,512,24,

%U 64,3072,64,96,32,192,64,1152,8,96,512,6144,128,2304,64,96,256,48

%N Number of divisors of 11^n+1.

%H Max Alekseyev, <a href="/A366688/b366688.txt">Table of n, a(n) for n = 0..325</a>

%F a(n) = sigma0(11^n+1) = A000005(A034524(n)).

%e a(4)=4 because 11^4+1 has divisors {1, 2, 7321, 14642}.

%p a:=n->numtheory[tau](11^n+1):

%p seq(a(n), n=0..100);

%o (PARI) a(n) = numdiv(11^n+1);

%Y Cf. A034524, A000005, A062308, A366683, A366686, A366687, A366689, A366690.

%Y Cf. A046798, A344897, A366714.

%K nonn

%O 0,1

%A _Sean A. Irvine_, Oct 16 2023