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 A366684 #7 Jan 04 2024 16:12:52
%S A366684 18,360,2880,46128,299646,7113600,35893440,686393568,5105934720,
%T A366684 80436972240,513593801496,14266630210560,62197735384584,
%U A366684 1165770116121600,9349887314805120,157025981601707904,909804651298728804,22898038082582016000,110086362807146183340
%N A366684 Sum of the divisors of 11^n-1.
%H A366684 Max Alekseyev, <a href="/A366684/b366684.txt">Table of n, a(n) for n = 1..316</a>
%F A366684 a(n) = sigma(11^n-1) = A000203(A024127(n)).
%e A366684 a(3)=2880 because 11^3-1 has divisors {1, 2, 5, 7, 10, 14, 19, 35, 38, 70, 95, 133, 190, 266, 665, 1330}.
%p A366684 a:=n->numtheory[sigma](11^n-1):
%p A366684 seq(a(n), n=1..100);
%t A366684 DivisorSigma[1, 11^Range[30]-1]
%Y A366684 Cf. A024127, A000203, A366710, A366666, A366681, A366682, A366683, A366685.
%K A366684 nonn
%O A366684 1,1
%A A366684 _Sean A. Irvine_, Oct 16 2023