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 A366616 #11 Apr 20 2025 20:12:39
%S A366616 2,4,4,12,4,8,8,16,8,32,16,32,8,16,8,96,8,16,32,32,16,576,16,16,16,32,
%T A366616 24,320,8,16,128,32,16,384,64,128,64,32,16,192,32,64,64,64,8,512,8,32,
%U A366616 32,128,128,768,32,32,64,128,128,384,8,64,64,64,16,24576,16
%N A366616 Number of divisors of 5^n+1.
%H A366616 Max Alekseyev, <a href="/A366616/b366616.txt">Table of n, a(n) for n = 0..471</a>
%F A366616 a(n) = sigma0(5^n+1) = A000005(A034474(n)).
%e A366616 a(3)=12 because 5^3+1 has divisors {1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126}.
%p A366616 a:=n->numtheory[tau](5^n+1):
%p A366616 seq(a(n), n=0..100);
%t A366616 DivisorSigma[0, 5^Range[0, 70] + 1] (* _Paolo Xausa_, Apr 20 2025 *)
%o A366616 (PARI) a(n) = numdiv(5^n+1);
%Y A366616 Cf. A000005, A034474, A057939, A074478, A366612, A366607, A366615, A366617, A366618.
%Y A366616 Cf. A046798, A366577, A366606, A366628, A366637, A366656, A366665, A344897, A366688, A366714.
%K A366616 nonn
%O A366616 0,1
%A A366616 _Sean A. Irvine_, Oct 14 2023